fax id: 3604 Innovative RoboClockTM Family Application Introduction This application note presents a unique application of the RoboClockTM, using its complex and precise waveform generation capability to implement PWM (Pulse Width Modulation) to enhance color images and increase the resolution of laser printers. The first section of this application note provides a brief description of RoboClock and presents three methods that the user can employ to configure it. Second, a brief background on image and resolution enhancement is presented. Finally, the required waveform to implement the image enhancement and the configuration of RoboClock is presented. Overview of RoboClock The CY7B991 and CY7B992, commonly known as RoboClock, are programmable skew clock buffers capable of generating thousands of various clocking combinations. As shown in Figure 1, the eight high drive outputs are arranged in four pairs, which can be configured by three-level inputs (HIGH, LOW, and MID logic level). The internal PLL is fully self-contained and does not require any external components to operate. The PLL buffer stages are differential, greatly enhancing the robustness of the PLL operation in terms of jitter over voltage, and temperature variations. TEST PHASE FREQ DET FB REF FILTER VCO AND TIME UNIT GENERATOR Basically, the PLL aligns the output clock in both phase and frequency with the reference clock. The simplest mode of operation is the low-skew output mode. In this mode the outputs are virtually skewless. The maximum skew is only a few hundred picoseconds. Please refer to the CY7B991/992 datasheet for various skew specifications. The second mode is the programmable skew mode. The outputs of RoboClock can be skewed (advanced and delayed) by increments of one time unit (tU), which is 0.7 to 1.5 ns, determined by the operating frequency and range of the PLL. tU = 1/(Fnom * N) Eq. 1 As shown in Table 1, the frequency range of the PLL is determined by the three-level FS input. For each frequency range, there is a corresponding integer "N" that can be used in Equation 1 to calculate tU. Up to 12tU skew can be achieved between the outputs of RoboClock (positive tU represents delaying the output with respect to REF and negative tU represents advancing the output with respect to REF). The third mode of operation is the Multi-function mode. In this mode the outputs may be multiplied by 2 or 4, divided by 2 or 4, or inverted. Most importantly, the skew features can be combined with multiply, divide, and invert functions. This results in, literally, over 26,000 timing configurations. For more detailed information on the operation of the RoboClock, please refer to the following application notes "Using the CY7B991 with the 50-MHz 486 Cache Module and the 40-MHz R3000" and "Everything You Need to Know About CY7B991/2 (RoboClock) and the RoboClock Family". This application note is meant to complement the topics discussed in above mentioned application notes. Table 1. Frequency Range Select and tU Calculation FS fNOM (MHz) 4F0 Min. Max. where N = LOW 15 30 44 22.7 MID 25 50 26 38.5 HIGH 40 80 16 62.5 4F1 4Q1 SELECT INPUTS (THREE LEVEL) 3F0 SKEW 3Q0 3F1 3Q1 SELECT 2Q0 2F0 2F1 MATRIX 2Q1 1Q0 1F0 1F1 1Q1 1 t U = -----------------------f NOM x N Approximate Frequency (MHz) At Which tU = 1.0 ns 4Q0 FS Usually, one of the outputs of RoboClock is used as the Feedback input. If the desired waveform is not directly generated by RoboClock, an imaginative user may run an output of RoboClock through a logic block, then send it back to the FB input of the RoboClock. Through this scheme, unlimited additional functions may be implemented by RoboClock. Note that in this case, all the other outputs of the RoboClock will be shifted by a period equal to the delay through the external logic block, because the PLL will align the FB input with the REF input, both in phase and frequency. Figure 1. Logic Block Diagram Cypress Semiconductor Corporation * 3901 North First Street * San Jose * CA 95134 * 408-943-2600 April 1994 - Revised June 23, 1998 Innovative RoboClock Family Application 3Qx is programmed to have +4tU of skew (3F1=HIGH, 3F0=LOW), the final output function observed on 3Qx will be +7tU. Cascading two RoboClocks in series will also dramatically increase the output possibilities. In this case, one of the outputs of the first stage will serve as the REF input for the second stage. Multiple feedback configurations are possible, which can result in an innovative set of outputs. One exception to this simple rule is that if a divided output is used as the FB input, then the other outputs will be multiplied by the same factor (2 or 4). The reason for this is that the PLL will force the FB to align with the REF both in phase and frequency. Therefore, if the FB term is programmed to divide by 2, the PLL will speed up twice to force the FB term to align with the REF frequency. As an example, if advance by 6tU and multiply by 4 function is required (-6tU and f*4), then RoboClock Configuration Methodologies Using One Small Table The entire set of programmable skew configurations is summarized in a single small table shown in Table 2. Every possible combination can be driven from this small table. For example, if +2tU is required from 3Qx (3Q0 or 3Q1) outputs, based on Table 2, the corresponding 3Fx inputs should be set as 3F1= MID and 3F0=HIGH. Any one of 1Qx, 2Qx, or 4Qx outputs may be used as FB input, by leaving its corresponding 1Fx, 2Fx, or 4Fx inputs floating (i.e., 1F1= MID, 1F0= MID). Note that Table 2 represents only the cases where the feedback is an output with no skew, divide, or invert function. Basically, a 0tU output is used for FB input. Final Function = -6tU - (divide by 4) => (-6tU and f*4) The solution for this example is to program 3Qx to divide by 4 (3F1=HIGH, 3F0=HIGH) and use it as FB, and program 4Qx to have -6tU of skew (4F1=LOW, 4F0=MID). The final function observed on 4Qx will be REF frequency multiplied by 4 and advanced by 6tU (-6tU and f*4). By this method, one can easily determine if a desired function can be implemented by RoboClock or not. RoboClock can generate a waveform composed of any two functions from two different outputs of Table 2. Table 2. Output Adjustment Configurations Function Selects Output Functions 1Q0, 1Q1, 2Q0, 2Q1 Using Three Tables for Multiple Outputs 1F1, 2F1, 3F1, 4F1 1F0, 2F0, 3F0, 4F0 LOW LOW -4tU LOW MID -3tU -6tU -6tU LOW HIGH -2tU -4tU -4tU MID LOW -1tU -2tU -2tU MID MID 0tU 0tU 0tU MID HIGH +1tU +2tU +2tU HIGH LOW +2tU +4tU +4tU HIGH MID +3tU +6tU +6tU HIGH HIGH +4tU Divide by 4 Inverted 3Q0, 3Q1 If multiple outputs with various functions are required, using the previous method could be a little cumbersome. All the possible combinations of RoboClock outputs are in three tables, illustrated in Tables 3 through 5. Each table represents all the possible output combinations with a given output connected to FB input. For example, once 3Qx output is used as FB input, then all the possible output combinations could be found in Table 4. These three tables are extremely valuable tools in determining what FB term to use and how to configure the RoboClock, when multiple outputs with various functions are required. 4Q0, 4Q1 Divide by 2 Divide by 2 Once the required multiple functions are determined in terms of tU, an effort should be made to locate one row in one of the three tables that contains the required functions. For example, if one of the desired functions is divide by 2 and delay 4tU (+4tU and f/2), then by observation, that choice can be located in row 1 of Table 3, row 3 of Table 4, and row 3 of Table 5. Now, the one to be selected as a solution would depend on what the other required functions are, because once an output, which is programmed to perform a certain function, is selected as FB input, all the outputs of a RoboClock are limited to a single row found in Tables 3 through 5. If in the previous example, the second required function happens to be invert and skew by 4tU (+4tU and INV), then the only solution is row 1 of Table 3. In this case 1Qx could be used as the FB input with its inputs hardwired to GND (1F1=LOW, 1F0=LOW), and 3F1=HIGH, 3F0=HIGH to generate (+4tU and f/2) function on 3Qx outputs, and set 4F1=HIGH, 4F0=HIGH to generate (+4tu and INV) function on 4Qx outputs. In this configuration, the 2Qx outputs could be programmed to have any one of 0tU through +8tU skew. For example, if +7tU is another required output, then 2F1=High, 2F0=Mid will generate +7tU skew on 2Qx. Note that even though the 1Qx outputs are programmed to have -4tU skew, they are forced by PLL to align with the REF frequency, therefore 1Qx output could be used as a 0t U output. Now, to generate additional output functions, if the feedback output is programmed to skew, divide or invert, then output functions of other outputs may not be directly read from Table 2. In this case, to figure out the final output function observed on the output, simply subtract whatever the feedback term is programmed to, from the output function programmed on the corresponding output. Therefore, by using only Table 2 and the following simple algorithm, every single combination of RoboClock can be figured out. Final Output Function = Output Function - FB Function If there is any ambiguity, the following example should clarify the use of this method. Let's say +7tU of delay is required. Obviously, +7tU is not a choice, available in Table 2. However, any two functions from two different outputs of Table 2 may be combined to achieve a desired function. For this example, there are several solutions, and only one of them will be presented. One way to achieve +7tU is to subtract -3tU from +4tU. +7tU = +4tU - (-3tU) The Table method is recommended for multiple outputs with various function requirements. If the exact required outputs cannot all be found in one row, then the designer can use the Therefore, if 1Qx output is programmed to have -3tU of skew (1F1=LOW, 1F0=MID), and used as the FB input, and if the 2 Innovative RoboClock Family Application hancement is gained with hardly any increase in the throughput of the processor or memory size. Therefore, this approach is a very economical way of gaining enhanced resolution. three tables to understand the design choices that are available within the three tables. Based on the design requirements, the user can make a judgement on what outputs must exactly meet the required specs, and what outputs may be slightly compromised. If the required outputs are not found in one row of the three tables, and no compromise can be made on the requirements, then two or more RoboClocks may be used to meet the specific required outputs. For obvious reasons, the entire laser printer industry is using some form of this technique. Various flavors of the same technique are being applied to different image-enhancement machines. The halftones or gray scales are common in most laser printers. The underlying technique is fairly simple. This is accomplished by modulating the laser beam, as opposed to the conventional "on" or "off" state of the laser beam, for the entire cycle time. The laser beam could be turned "on" or "off" 25%, 50%, 75% or 100% of the period. By this, large and small dots can be produced on a given image, therefore gaining much higher "perceived" resolution compared with images constructed by only one size dot. The varying size dots produce much smoother text files and generate much sharper images through shades of gray. Refer to Figure 2a and 2b. The same idea is used in color image enhancement where much smoother and more pleasant images may be produced in a given color image by dilating black dots and shrinking the red. This filtering or color enhancement feature can be used to produce various special effects, or simply be employed to create more appealing color images. Please refer to Figure 3a and Figure 3b To further clarify this technique, the true resolution, technically, still remains the same, but the images are "perceived" to be higher resolution. It does not matter how the "better image" was created, as long as it looks good and the cost of the hardware is affordable. Using RoboClock in Resolution Enhancement of a Laser Printer Background Laser printers are no different from any other electrical systems, in that the higher the resolution or the accuracy of the system, the higher the complexity and cost of the system. It has been and will always be the goal of system and design engineers to achieve the highest performance and resolution at the lowest cost In the case of a laser printer, to achieve higher resolution than the nominal low-end 300 DPI (dot per inch), the throughput of the processor, size of the memory, and the glue logic should increase accordingly. In many cases, the additional hardware cost does not justify the enhancement in the resolution. A few years ago, a new technique called Resolution Enhancement Technology (RET) was developed by Hewlett Packard. The main advantage of this technique versus conventional resolution enhancement techniques is that the resolution en- . a. Standard unmodulated b. Modulated laser beam with shorter "on" periods and variable-size dots. Figure 2. Laser Images . a. Black dot dilated b. Red dot shrunk Figure 3. Color Enhancements 3 Innovative RoboClock Family Application tp = 15 ns REF (66.67 MHz) F F +4tU 100% HIGH 75% HIGH 50% HIGH 25% HIGH 100% LOW 75% LOW 50% LOW 25% LOW Figure 4. Generated Waveforms Design Implementation The 66.67-MHz system clock is fed to the REF input of the RoboClock. RoboClock generates very precise waveforms and, with one level of gating, all the six modulated waveforms are produced and fed to the 8:1 MUX. For this design, RoboClock generates precise 90-degree phase-shifted, true and complemented versions of the 66.67-MHz REF input frequency. Note that only six waveforms are generated. The "100% on" and "100% off" modes are hardwired HIGH and LOW to the 8:1 MUX. Three bits of the SRAM are used to select one out of eight possible modulated signals. The output of very fast MUX is directly sent to the laser head. Therefore, all eight levels of modulated waveforms are present at the input of the MUX at all times. Only one is routed to the laser head, depending on the required modulation level stored in the SRAM. RoboClock is used to generate precise complex waveforms needed for laser beam modulation. The particular laser system discussed in this application note requires eight levels of modulation, which consists of 100% on, 75% on, 50% on, 25% on, 100% off, 75% off, 50% off, and 25% off. The eight waveforms are shown in Figure 4. Note that all waveforms are synchronized to the rising edge of the system clock.Analyzing the entire circuitry of the laser printer is beyond the scope of this application note, and only the waveform modulation section is discussed. The system clock runs at 66.67 MHz, which translates into 15 ns cycle time. The simplified diagram of the modulation section is shown in Figure 5. The modulation section consists of a RoboClock, a 256K*4 SRAM that contains the pixel information, four NOR gates with complemented outputs, and an 8:1 MUX. In this application, since the laser head interface uses ECL levels, 500 ps ECL NOR gate with complemented outputs (MC10E101) and ECL 8:1 MUX (MC10E163) is used. Unused inputs of the quad four input NOR gates are tied LOW. The TTL outputs of CY7B991 are translated into ECL levels by Cypress Semiconductor high-speed, low-skew TTL to ECL translator (CY10E384L). To keep the modulation logic diagram simple, the translate block is not shown in Figure 5. Note that, generally, 74AS logic parts are used to implement external logic functions, which requires no translate logic to interface with RoboClock. Generally, one should be very cautious about using the output of a MUX, since during the period when MUX select bits are changing, the MUX output will usually be glitching, until the MUX select bits are stabilized. This behavior is due to the fact that all the select bits do not arrive at exactly the same time. Even if they did arrive at the same time, delay path variations and logic switching internal to MUX may create a glitch on the output. As a word of caution, the above mentioned scheme should not be used for a clocking scheme. When a new MUX input is selected, there will probably be a glitch on the output. If the first cycle glitch can be tolerated or masked, then this scheme can be used for clock distribution. A delayed clocked version of the MUX output could be safely used for 4 Innovative RoboClock Family Application clock distribution. Obviously, the delay should be larger than the maximum propagation delay of MUX. For this particular application, the glitch is not as important, because the total duration of ON and OFF times of the laser beam is the concern, not the rising or falling edges of the waveform. Also, the laser head is turned off during the MUX address selection, totally masking any possible glitches. have the same number of loads. It is very important during layout to match all the trace lengths from RoboClock to NOR gates and from the NOR gates to the MUX to prevent undesirable skew, which will translate into phase shift and pulsewidth variation on the laser beam. Over voltage and temperature variation, all the outputs of the RoboClock are very stable. The PLL inside the RoboClock is constructed from differential stages, which makes it self-compensating against voltage and temperature variations. Consequently, RoboClock generates robust output waveforms in terms of phase and frequency. The external OR gates may distort the waveform due to the effects of voltage and temperature variation. Configuring RoboClock and Design Analysis A close observation of waveforms shown in Figure 5 reveals the fundamental idea behind generating all six modulated waveforms. Simply by gating the 90-degree phase-shifted REF with the true and complemented version of the REF clock, all six waveforms are generated. For simplicity's sake, lets call the 90-degree phase-shifted waveform +4tU, 66.67-MHz clock F, and the inverted clock F. Let's look at how each one is generated. Earlier, the 90-degree phase-shifted waveform was equated with +4tU. Let's see how that was derived. Based on Table 1, each time unit is calculated by the following equation: 75% HIGH: (+4tU) OR (F) tU = 1/(Fnom * N) 50% HIGH: F Where, as indicated in the Table 1, N can be any one of 44, 26, or 16 integer numbers, depending on the maximum output frequency of the RoboClock. Since the output frequency is 66.67 MHz, then FS is selected to be HIGH (frequency range of 40 to 80 MHz), N = 16, and Fnom = 66.67 MHz. By simply plugging the numbers in the Equation 2, the time unit or the tU can be calculated as: 25% HIGH: (+4tU) NOR (F) 75% LOW: (+4tU) NOR (F) 50% LOW: F 25% LOW: (+4tU) OR (F) Note that very fast NOR gates with true and complemented outputs were selected to achieve uniform delay for all outputs. Also, the 50% HIGH and 50% LOW signals are routed OR gates configured as buffers to ensure matched delay signals. Please note that all three RoboClock outputs, +4tU, F, and F, tU = 1/(66.67 MHZ * 16) tU = 0.9375 ns CY7B991 100% HIGH FB 66.67 MHz VCC LOW 4Q0 4Q1 4F1 3F1 2F0 GND 2F1 1F0 F 3Q1 75% LOW F 50% LOW 2Q0 2Q1 25% LOW LOW TO LASER HEAD QA A3 100% LOW LOW 3Q0 8:1 MUX A2 25% HIGH +4tU A0 A1 50% HIGH FS 3F0 HIGH 75% HIGH REF 4F0 Eq. 2 QA A4 A5 A6 A7 1Q1 S2 S1 S0 1Q0 1F1 TEST MUX SELECT BITS FROM SRAM GND Figure 5. Simplified Laser Modulation Diagram 5 Innovative RoboClock Family Application Therefore, 16/4 = 4 time units, in FS = HIGH mode, represents a 90 degree phase shift. In terms of phase shift, if 66.67 MHz or 15-ns cycle time is 360 degrees, then the 90-degree phase-shift is essentially 15 ns divided by 4. The same simple methodology can be used to figure out the number of time units of delay or advance to implement a n arbitrary degree of phase shift. The number of units of skew (TU needed for an arbitrary phase shift is calculated as follows: 90 Degree Phase Shift = 15 ns / 4 = 3.75 ns Therefore, the number of time units to shift to obtain 90-degree phase-shift, is simply derived by dividing 3.75 ns by tU. Number of Time Units = 3.75 ns / 0.9375 = 4 N - phaseshift #T U = ---------------------------------------360 Therefore, in FS = HIGH mode, 4 tU translates into 90-degree phase-shift. An observant reader might have already noticed the fact that in FS = HIGH mode, N is equal to 16, based on Table 1. This means that, in FS = HIGH mode, an entire cycle or 360 degrees, is equivalent to the delay through 16 stages of ring oscillator, and each stage represents one tU (In FS = LOW the number of delay stages or N is 44 and in FS = MID it is 26. As shown in Figure 6 note that the actual number of ring oscillator buffer stages is half the N, because each cycle contains a LOW and HIGH period, which means to complete a full cycle the signal propagates through the ring oscillator twice.) In order to derive a 90-degree phase-shift, all one needs to do is to multiply N by 1/4 (where 90/360 = 1/4 cycle). Vcon FS -6 -4 -3 -2 -1 0 +1 +2 Eq. 3 Rounding this number to the nearest integer will introduce a small phase error from the desired phase shift. For example, if 60 degree phase shift is required when FS = LOW, then: Required Phase Shift = 60/360 = 1/6 cycle Number of Time Units = N * 1/6 = 44/6 = 7.33 tU Since the number of PLL stages for each FS mode is an integer number, then the nearest time unit shift, in this case, will be seven. Obviously, this will create a phase error of 0.33 tU. , +3 +4 +6 /2 /4 1F0 1Q0 1F1 1Q1 2F0 2Q0 2F1 2Q1 3F0 3Q0 3F1 3Q1 4F0 4Q0 4F1 4Q1 Distributed-Phase Taps Divided & Inverted Taps Figure 6. Distributed-Phase Clock Oscillator and Output Adjust Matrix 6 Innovative RoboClock Family Application purposes. Often, during prototyping phase, some modification in the clock or the waveform is required. Let's go back and discuss how the +4tU, F and F waveforms are generated by RoboClock. Since multiple outputs from a single RoboClock is expected, as an exercise, let's use the three-table method. There are several solutions for the current requirement; only one of the simplest is presented. By observing Table 3, titled as "1Qx/2Qx Output Connected to FB Input," one may select the 1Q0 to be used as FB, and leave the corresponding inputs floating (1F0=1F1=MID). Thus, essentially, we have access to all the terms available in row two of the given table. Now, by selecting the inputs, the RoboClock may be configured to generate various waveforms. By setting 2F0=2F1=MID or floating the 2Fx inputs, the 2Q0 and 2Q1 will generate the required F signal (also, 1Qx could have been used for F signal). Setting 3F0=LOW and 3F1=HIGH will generate +4tU signal at 3Q0 and 3Q1. Finally, setting 4F0=4F1=HIGH will generate the F signal. As mentioned earlier, by fixing the feedback term, in this case, all the elements of the 2nd row of Table 3 are available for the user. RoboClock is a flexible clock distribution buffer that may be reconfigured easily during the prototyping phase of a design. For example, if instead of generating a 0 TU output on 2Qx, it is required to have the 2Qx signals advanced by 2tU, then this can be accomplished simply by setting 2F0=HIGH and 2F1=LOW. This is one of the commonly used features of RoboClock that offers thousands of variations for prototyping RoboClock, with its thousands of configurations, resolves some of the unexpected timing problems. In fact, during prototyping, if multiple timing variations are expected, it is advised to use a three-state register to drive the RoboClock inputs. Then, each output of the register must have a 10K pull-up and 10K pull-down resistor, to ensure that MID level is held at half the supply voltage when the register is three-stated. In this case, the user may write a word in the input register, and by doing so, reconfigure the entire operation of the RoboClock, without using any jumpers. Note that not all the inputs need to be reconfigurable for a given design. Often, a couple of reconfigurable signals are all that is needed. In that case, most inputs may be hardwired and the inputs needed to reconfigure various outputs may be registered with the 10K pull-up and pull-down resistors. Summary RoboClock was used to generate very precise complex waveforms to enhance color images and increase the resolution of laser printers. Even though RoboClock is widely used for clock distribution, this application note presented an alternative use of RoboClock for complex precise waveform generation. Table 3. 1Qx or 2Qx Output Connected to FB Input (Part 1) 1F0 (2F0) L L L M M M H H H L M H L M H L M H Configuration Block 1F1 (2F1) 2Qx Output Section 2Qx(1Qx) Outputs with respect to REF 2F1 L L L M (1F1) 2F0 L M H L (1F0) Output Selection Block Feedback Section 1Qx(2Qx)FB 0t -1t -2t -3t -4t -5t -6t -7t -8t +1t 0t -1t -2t -3t -4t -5t -6t -7t +2t +1t 0t -1t -2t -3t -4t -5t -6t 7 +3t +2t +1t 0t -1t -2t -3t -4t -5t M M H H H M H L M H +4t +3t +2t +1t 0t -1t -2t -3t -4t +5t +4t +3t +2t +1t 0t -1t -2t -3t +6t +5t +4t +3t +2t +1t 0t -1t -2t +7t +6t +5t +4t +3t +2t +1t 0t -1t +8t +7t +6t +5t +4t +3t +2t +1t 0t Innovative RoboClock Family Application Table 3. 1Qx or 2Qx Output Connected to FB Input (Part 2) 1F0 (2F0) L L L M L H M L M M M H H L H M H H Configuration Block 1F1 (2F1) 3Qx Output Section 3Qx Outputs with respect to REF L L L 3F1 3F0 Output Selection Block Feedback Section 1Qx(2Qx)FB M M M H H H L M H L M H L M H +4t, f/2 +3t, f/2 +2t, f/2 +1t, f/2 0t, f/2 -1t, f/2 -2t, f/2 -3t, f/2 -4t, f/2 -2t 0t +2t +4t +6t +8t +10t +4t, f/4 -3t -1t +1t +3t +5t +7t +9t +3t,f/4 -4t -2t 0t +2t +4t +6t +8t +2t,f/4 -5t -3t -1t +1t +3t +5t +7t +1t,f/4 -6t -4t -2t 0t +2t +4t +6t 0t,f/4 -7t -5t -3t -1t +1t +3t +5t -1t,f/4 -8t -6t -4t -2t 0t +2t +4t -2t,f/4 -9t -7t -5t -3t -1t +1t +3t -3t,f/4 -10t -8t -6t -4t -2t 0t +2t -4t,f/4 M M M H H H Table 3. 1Qx or 2Qx Output Connected to FB Input (Part 3) 1F0 (2F0) L L L M L H M L M M M H H L H M H H Configuration Block 1F1 (2F1) 4Qx Output Section 4Qx Outputs with respect to REF L L L 4F1 Output Selection Block Feedback Section 1Qx(2Qx)FB 4F0 L M H L M H L M H +4t, f/2 +3t, f/2 +2t, f/2 +1t, f/2 0t, f/2 -1t, f/2 -2t, f/2 -3t, f/2 -4t, f/2 -2t 0t +2t +4t +6t +8t +10t -3t -1t +1t +3t +5t +7t +9t -4t -2t 0t +2t +4t +6t +8t -5t -3t -1t +1t +3t +5t +7t -6t -4t -2t 0t +2t +4t +6t -7t -5t -3t -1t +1t +3t +5t -8t -6t -4t -2t 0t +2t +4t -9t -7t -5t -3t -1t +1t +3t -10t -8t -6t -4t -2t 0t +2t +4t INV +3t INV +2t INV +1t INV 0t INV -1t INV -2t INV -3t INV -4t INV 8 Innovative RoboClock Family Application Table 4. 3Qx Output Connected to FB Input (Part 1) 3QxFB 1Qx, 2Qx Output Section Configuration Block Feedback Section 1Qx (2Qx) Outputs with respect to REF 1F1 (2F1) L L L M M M H H H 1F0, (2F0) L M H L M H L M H 3F0 L L -4t, f*2 -3t f*2 -2t f*2 -1t f*2 0t f*2 +1t f*2 +2t f*2 +3t f*2 +4t f*2 L M +2t +3t +4t +5t +6t +7t +8t +9t +10t L H 0t +1t +2t +3t +4t +5t +6t +7t +8t M L -2t -1t 0t +1t +2t +3t +4t +5t +6t M M -4t -3t -2t -1t 0t +1t +2t +3t +4t M H -6t -5t -4t -3t -2t -1t 0t +1t +2t H L -8t -7t -6t -5t -4t -3t -2t -1t 0t H M -10t -9t -8t -7t -6t -5t -4t -3t -2t H H -4t f*4 -3t f*4 -2t f*4 -1t f*4 0t f*4 +1t f*4 +2t f*4 +3t f*4 +4t f*4 Output Selection Block 3F1 Table 4. 3Qx Output Connected to FB Input (Part 2) 3QxFB 3Qx Output Section Configuration Block Feedback Section 4Qx Outputs with respect to REF 4F1 L L L M M M H H H 4F0 L M H L M H L M H 3F0 L L 0t -6t, f*2 -4t, f*2 -2t, f*2 0t f*2 +2t, f*2 +4t, f*2 +6t, f*2 INV, f*2 L M +6t, f/2 0t +2t +4t +6t +8t +10t +12t +6t, INV L H +4t, f/2 -2t 0t +2t +4t +6t +8t +10t +4t, INV M L +2t, f/2 -4t -2t 0t +2t +4t +6t +8t +2t, INV M M 0t, f/2 -6t -4t -2t 0t +2t +4t +6t 0t, INV M H -2t, f/2 -8t -6t -4t -2t 0t +2t +4t -2t, INV H L -4t, f/2 -10t -8t -6t -4t -2t 0t +2t -4t, INV H M -6t, f/2 -12t -10t -8t -6t -4t -2t 0t -6t, INV H H 0t, f*2 -6t, f*4 -4t, f*4 -2t, f*4 0t, f*4 +2t, f*4 +4t, f*4 +6t, f*4 INV, f*4 Output Selection Block 3F1 9 Innovative RoboClock Family Application Table 5. 4Qx Output Connected to FB Input (Part 1) 4QxFB 1Qx, 2Qx Output Section Configuration Block Feedback Section 1Qx, 2Qx Outputs with respect to REF 1F1, 2F1 L L L M M M H H H 1F0, 2F0 L M H L M H L M H 4F0 L L -4t, f*2 -3t, f*2 -2t, f*2 -1t, f*2 0t, f*2 +1t, f*2 +2t, f*2 +3t, f*2 +4t, f*2 L M +2t +3t +4t +5t +6t +7t +8t +9t +10t L H 0t +1t +2t +3t +4t +5t +6t +7t +8t M L -2t -1t 0t +1t +2t +3t +4t +5t +6t M M -4t -3t -2t -1t 0t +1t +2t +3t +4t M H -6t -5t -4t -3t -2t -1t 0t +1t +2t H L -8t -7t -6t -5t -4t -3t -2t -1t 0t H M -10t -9t -8t -7t -6t -5t -4t -3t -2t H H -4t, INV -3t, INV -2t, INV -1t, INV 0t, INV +1t, INV +2t, INV +3t, INV +4t, INV Output Selection Block 4F1 Table 5. 4Qx Output Connected to FB Input (Part 2) 4QxFB 1Qx, 2Qx Output Section Configuration Block Feedback Section 4Qx Outputs with respect to REF 3F1 L L L M M M H H H 3F0 L M H L M H L M H 4F0 L L 0t -6t, f*2 -4t, f*2 -2t, f*2 0t f*2 +2t, f*2 +4t, f*2 +6t, f*2 0t, f/2 L M +6t, f/2 0t +2t +4t +6t +8t +10t +12t +6t, f/4 L H +4t, f/2 -2t 0t +2t +4t +6t +8t +10t +4t, f/4 M L +2t, f/2 -4t -2t 0t +2t +4t +6t +8t +2t, f/4 M M 0t, f/2 -6t -4t -2t 0t +2t +4t +6t 0t, f/4 M H -2t, f/2 -8t -6t -4t -2t 0t +2t +4t -2t, f/4 H L -4t, f/2 -10t -8t -6t -4t -2t 0t +2t -4t, f/4 H M -6t, f/2 -12t -10t -8t -6t -4t -2t 0t -6t, f/4 H H INV, f/2 -6t, INV -4t, INV -2t, INV 0t, INV +2t, INV +4t, INV +6t, INV INV, f/4 Output Selection Block 4F1 RoboClock is a trademark of Cypress Semiconductor Corporation. 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