XC18V00 Series In-System Programmable Configuration PROMs
R
Reset Activation
On power up, OE/RESET is held low until the XC18V00 is
active (1 ms). OE/RESET is connected to an external resis-
tor to pull OE/RESET HIGH releasing the FPGA INIT and
allowing configuration to begin. If the power drops below
2.0V, the PROM resets. OE/RESET polarity is
not
program-
mable. See
for power-up requirements.
remains in a high-impedance state regardless of the state of
the OE input. JTAG pins TMS, TDI and TDO can be in a
high-impedance state or High. See
5V Tolerant I/Os
The I/Os on each re-programmable PROM are fully 5V tol-
erant even through the core power supply is 3.3V. This
allows 5V CMOS signals to connect directly to the PROM
inputs without damage. In addition, the 3.3V V
CCINT
power
supply can be applied before or after 5V signals are applied
to the I/Os. In mixed 5V/3.3V/2.5V systems, the user pins,
the core power supply (V
CCINT
), and the output power sup-
ply (V
CCO
) can have power applied in any order. This
makes the PROM devices immune to power supply
sequencing issues.
3.6V
Recommended Operating Range
3.0V
Volts
Recommended
V
CCINT
Rise
Time
0V
0ms 1ms
Time (ms)
Customer Control Bits
50ms
ds026_10_061103
Figure 8:
V
CCINT
Power-Up Requirements
Standby Mode
The PROM enters a low-power standby mode whenever
CE is asserted High. The address is reset. The output
Table 7:
Truth Table for PROM Control Inputs
Control Inputs
OE/RESET
High
Low
High
Low
CE
Low
Low
High
High
Internal Address
The XC18V00 PROMs have various control bits accessible
by the customer. These can be set after the array has been
programmed using “Skip User Array” in Xilinx iMPACT soft-
ware. The iMPACT software can set these bits to enable the
optional JTAG read security, parallel configuration mode, or
CF-->D4 pin function. See
Outputs
DATA
Active
High-Z
High-Z
High-Z
High-Z
CEO
High
Low
High
High
High
I
CC
Active
Reduced
Active
Standby
Standby
If address < TC
(1)
: increment
If address > TC
(1)
: don’t change
Held reset
Held reset
Held reset
Notes:
1. TC = Terminal Count = highest address value. TC + 1 = address 0.
12
1-800-255-7778
DS026 (v4.0) June 11, 2003
Product Specification
XILINX [ XILINX, INC ]
