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Data Sheet
June 1999
ORCA Series 2 FPGAs
Lucent Technologies Inc.
67
Special-Purpose Pins Special-Purpose Pins (Become User I/O After Configuration) (continued)
M0, M1, M2
I
During powerup and initialization, M0—M2 are used to select the configuration mode
with their values latched on the rising edge of INIT. See Table 7 for the configuration
modes. During configuration, a pull-up is enabled, and after configuration, the pins are
user-programmable I/O*.
M3
I
During powerup and initialization, M3 is used to select the speed of the internal oscilla-
low, the oscillator frequency is 10 MHz. When M3 is high, the oscillator is 1.25 MHz.
During configuration, a pull-up is enabled, and after configuration, this pin is a user-pro-
grammable I/O pin*.
TDI, TCK, TMS
I
If boundary scan is used, these pins are Test Data In, Test Clock, and Test Mode Select
inputs. If boundary scan is not selected, all boundary-scan functions are inhibited once
configuration is complete, and these pins are user-programmable I/O pins. Even if
boundary scan is not used, either TCK or TMS must be held at logic 1 during configura-
tion. Each pin has a pull-up enabled during configuration*.
HDC
O
High During Configuration is output high until configuration is complete. It is used as a
control output indicating that configuration is not complete. After configuration, this pin is
a user-programmable I/O pin*.
LDC
O
Low During Configuration is output low until configuration is complete. It is used as a
control output indicating that configuration is not complete. After configuration, this pin is
a user-programmable I/O pin*.
INIT
I/O
INIT is a bidirectional signal before and during configuration. During configuration, a
pull-up is enabled, but an external pull-up resistor is recommended. As an active-low
open-drain output, INIT is held low during power stabilization and internal clearing of
memory. As an active-low input, INIT holds the FPGA in the wait-state before the start of
configuration. After configuration, the pin is a user-programmable I/O pin*.
CS0, CS1, WR, RD
ICS0, CS1, WR, RD are used in the asynchronous peripheral configuration modes. The
FPGA is selected when CS0 is low and CS1 is high. When selected, a low on the write
strobe, WR, loads the data on D[7:0] inputs into an internal data buffer. WR, CS0, and
CS1 are also used as chip selects in the slave parallel mode.
A low on RD changes D7 into a status output. As a status indication, a high indicates
ready and a low indicates busy. WR and RD should not be used simultaneously. If they
are, the write strobe overrides. During configuration, a pull-up is enabled, and after con-
figuration, the pins are user-programmable I/O pins*.
A[17:0]
O
During master parallel configuration mode, A[17:0] address the configuration EPROM.
During configuration, a pull-up is enabled, and after configuration, the pins are user-
programmable I/O pins*.
D[7:0]
I
During master parallel, peripheral, and slave parallel configuration modes, D[7:0]
receive configuration data and each pin has a pull-up enabled. After configuration, the
pins are user-programmable I/O pins*.
DOUT
O
During configuration, DOUT is the serial data output that can drive the DIN of daisy-
chained slave LCA devices. Data out on DOUT changes on the falling edge of CCLK.
After configuration, DOUT is a user-programmable I/O pin*.
Table 17. Pin Descriptions (continued)
Symbol
I/O
Description
* The FPGA States of Operation section contains more information on how to control these signals during start-up. The timing of DONE
release is controlled by one set of bit stream options, and the timing of the simultaneous release of all other configuration pins (and the acti-
vation of all user I/Os) is controlled by a second set of options.
Pin Information (continued)