Altera Corporation 7
Configuration Devices for APEX & FLEX Devices Data Sheet
The configuration device’s
OE
and
nCS
pins control the tri-state buffer on
the
DATA
output pin, and enable the address counter (and the oscillator in
EPC2, EPC1, and EPC1441 devices). When
OE
is driven low, the
configuration device resets the address counter and tri-states its
DATA
pin.
The
nCS
pin controls the output of the configuration device. If
nCS
is held
high after the
OE
reset pulse, the counter is disabled and the
DATA
output
pin is tri-stated. When
nCS
is driven low, the counter and
DATA
output pin
are enabled. When
OE
is driven low again, the address counter is reset and
the
DATA
output pin is tri-stated, regardless of the state of
nCS
.
1
The EPC2, EPC1, and EPC1441 devices determine the operation
mode and whether the APEX 20K, FLEX 10K, FLEX 8000, or
FLEX 6000 protocols should be used when
OE
is driven high.
When the configuration device has driven out all of its data and has
driven
nCASC
low, the device tri-states the
DATA
pin to avoid contention
with other configuration devices. Upon power-up, the address counter is
reset automatically.
The EPC2 device allows the user to initiate configuration of the FLEX or
APEX device via an additional pin, called
nINIT_CONF
, that can be tied to
the
nCONFIG
pin of the FLEX or APEX device(s) to be configured. A JTAG
instruction causes the EPC2 device to drive
nINIT_CONF
low, which in
turn pulls
nCONFIG
low. The EPC2 device then drives
nINIT_CONF
high to
start configuration. When the JTAG state machine exits this state,
nINIT_CONF
releases
nCONFIG
and configuration is initiated.
1
An EPC2 device can be programmed with a POF generated for
an EPC1 or EPC1441 device (except when configuring
FLEX 8000 devices). In addition, an EPC1 device can be
programmed using a POF
generated for an EPC1441 device.
APEX 20K, FLEX 10K & FLEX 6000 Device Configuration
APEX 20K and FLEX 10K devices can be configured with EPC2, EPC1, or
EPC1441 devices. FLEX 6000 devices can be configured with EPC1 or
EPC1441 devices. The EPC2, EPC1, or EPC1441 device stores
configuration data in its EPROM array and serially clocks data out with
an internal oscillator. The
OE
,
nCS
, and
DCLK
pins supply the control
signals for the address counter and the output tri-state buffer. The
configuration device sends a serial bitstream of configuration data to its
DATA
pin, which is routed to the
DATA0
or
DATA
input pin on the
APEX 20K, FLEX 10K, or FLEX 6000 device. One EPC1441 device can
configure an EPF10K10, EPF10K20, or EPF10K30 device. Figure 4 shows
an APEX 20K, FLEX 10K, or FLEX 6000 device configured with a single
EPC2, EPC1, or EPC1441 device.