XC3S100E Datasheet, PDF (88/193 Pages) Xilinx, Inc – DC and Switching Characteristics

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Functional Description
After configuration, all of the interface pins except DONE
and PROG_B are available as user I/Os. Alternatively, the
bidirectional SelectMAP configuration interface is available
after configuration. To continue using SelectMAP mode, set
the Persist bitstream generator option to Yes. The external
host can then read and verify configuration data.
The Slave Parallel mode is also used with BPI mode to cre-
ate multi-FPGA daisy-chains. The lead FPGA is set for BPI
mode configuration; all the downstream daisy-chain FPGAs
are set for Slave Parallel configuration, as highlighted in
Figure 56.
Table 55: Slave Parallel Mode Connections
Pin Name FPGA Direction
Description
HSWAP
Input
User I/O Pull-Up Control. When
Low during configuration, enables
pull-up resistors in all I/O pins to
respective I/O bank V_CCO input.
0: Pull-ups during configuration
1: No pull-ups
M[2:0]
Input
Mode Select. Selects the FPGA
configuration mode.
D[7:0]
Input
Data Input.
BUSY
Output
Busy Indicator.
CSI_B
Input
Chip Select Input. Active Low.
RDWR_B
Input
Read/Write Control. Active Low
write enable.
CCLK
LDC[2:0]
HDC
Input
Output
Configuration Clock. If CCLK
PCB trace is long or has multiple
connections, terminate this output
to maintain signal integrity.
Low During Configuration.
Output
High During Configuration.
During Configuration
Drive at valid logic level
throughout configuration.
After Configuration
User I/O
M2 = 1, M1 = 1, M0 = 0 Sampled User I/O
when INIT_B goes High.
Byte-wide data provided by host.
FPGA captures data on rising
CCLK edge.
User I/O. If bitstream
option Persist=Yes,
becomes part of
SelectMap parallel
peripheral interface.
If CCLK frequency is < 50 MHz,
this pin may be ignored. When
High, indicates that the FPGA is
not ready to receive additional
configuration data. Host must
hold data an additional clock
cycle.
User I/O. If bitstream
option Persist=Yes,
becomes part of
SelectMap parallel
peripheral interface.
Must be Low throughout
configuration.
User I/O. If bitstream
option Persist=Yes,
becomes part of
SelectMap parallel
peripheral interface.
Must be Low throughout
configuration.
User I/O. If bitstream
option Persist=Yes,
becomes part of
SelectMap parallel
peripheral interface.
External clock.
User I/O If bitstream
option Persist=Yes,
becomes part of
SelectMap parallel
peripheral interface.
These pins are not used during
configuration. Low throughout
configuration.
User I/O
This pin is not used during
configuration. High throughout
configuration.
User I/O
DS312-2 (v1.1) March 21, 2005
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