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XRT94L43
12
REV. 1.0.2
SONET/SDH OC-12 TO 12XDS3/E3 MAPPER
T21
PDBEN_L
I
TTL
Bi-directional Data Bus Enable Input Pin:
This input pin permits the user to either enable or tri-state the Bi-Directional
Data Bus pins (D[7:0]), as described below.
Setting this input pin "low" enables the Bi-directional Data bus. Setting this
input "high" tri-states the Bi-directional Data Bus.
U25
PBLAST_L
I
TTL
Last Burst Transfer Indicator input Pin:
If the Microprocessor Interface is operating in the Intel-I960 Mode, then this
input pin is used to indicate (to the Microprocessor Interface block) that the
current data transfer is the last data transfer within the current burst opera-
tion.
The Microprocessor should assert this input pin (by toggling it "Low") in
order to denote that the current READ or WRITE operation (within a
BURST operation) is the last operation of this BURST operation.
NOTE:
If the user has configured the Microprocessor Interface to operate
in the Intel-Asynchronous, the Motorola-Asynchronous or the
Power PC 403 Mode, then he/she should tie this input pin to GND.
AC26
PINT_L
O
CMOS
Interrupt Request Output:
This active-Low, active-low output signal will be asserted when the
XRT94L43 is requesting interrupt service from the Microprocessor. This
output pin should typically be connected to the Interrupt Request input of
the Microprocessor.
L24
RESET_L
I
TTL
Reset Input:
When this active-Low signal is asserted, the XRT94L43 will be asynchro-
nously reset. When this occurs, all outputs will be tri-stated and all on-chip
registers will be reset to their default values.
M26
FULL_ADDR_
SEL
I
TTL
Full Address Select input pin:This input pin, along with
"DIRECT_ADD_SEL" (pin M23) must both be pulled "HIGH" in order to
configure the Microprocessor Interface block to operate in the "Full
Address" Mode.If the Microprocessor Interface is configured to operate in
the "Full Address" Mode, then it will then provide a 16-bit Address Bus
(which is sufficient to "Directly Address" all of the on-chip registers.
M23
DIRECT_ADD
_SEL
I
TTL
Direct Address Select input pin:This input pin, along with
"FULL_ADDR_SEL" (pin M26) must both be pulled "HIGH" in order to con-
figure the Microprocessor Interface block to operate in the "Full Address"
Mode.If the Microprocessor Interface is configured to operate in the "Full
Address" Mode, then it will then provide a 16-bit Address Bus (which is suf-
ficient to "Directly Address" all of the on-chip registers.
MICROPROCESSOR INTERFACE
PIN #SIGNAL NAME
I/O
SIGNAL
TYPE
DESCRIPTION