
XRT72L53
á
THREE CHANNEL DS3/E3 FRAMER IC WITH HDLC CONTROLLER
REV. P1.1.7
PRELIMINARY
29
R18
CS
I
Chip Select Input:
This active-low input signal selects the Microprocessor Interface Sec-
tion of the Framer device and enables READ/WRITE operations
between the Local Microprocessor and the Framer on-chip registers
and RAM locations.
R19
ALE_AS
I
Address Latch Enable/Address Strobe:
This input is used to latch the address (present at the Microprocessor
Interface Address Bus, A(10:0)) into the Framer Microprocessor Inter-
face circuitry and to indicate the start of a READ/WRITE cycle. This
input is active-high in the Intel Mode (MOTO = "Low") and active-low in
the Motorola Mode (MOTO = "High").
R20
A[0]
I
Address Bus Input (Microprocessor Interface) - LSB (Least Signifi-
cant Bit):
(Please see description for A(10))
T1
RLOL[2]
I
Receive Loss of Lock Indicator Input - Channel 2 (from the DS3/E3
LIU IC):
See Description for Pin B8
T3
RxOOF[2]
O
Receive Out of Frame Indicator - Channel 2:
See Description for Pin A3
T17
RxClk[2]
O
Receive Clock Output signal for Serial and Nibble-Parallel Data
Interface - Channel 2:
See Description for Pin D20
T18
NibbleIntf
I
Nibble Interface Select Input Pin:
This input pin allows the user to configure the Transmit Payload Data
Input Interface and the Receive Payload Data Output Interface to oper-
ate in either the Serial-Mode or the Nibble/Parallel-Mode.
Setting this input pin "High" configures the Transmit and Receive Termi-
nal Interfaces to operate in the Nibble/Parallel-Mode. In this mode, the
“Transmit Payload Data Input Interface” block will accept the “outbound”
payload data (from the Terminal Equipment) in a “nibble-parallel” man-
ner via the “TxNib[3:0]” input pins. Further, the “Receive Payload Data
Output Interface” block will output the “inbound” payload data (to the
Terminal Equipment) in a “nibble-parallel” manner via the “RxNib[3:0]”
output pin.
Setting this input pin "Low" configures the Transmit and Receive Termi-
nal Interfaces to operate in the Serial Mode. In this mode, the “Transmit
Payload Data Input Interface” block will accept the “outbound” payload
data (from the Terminal Equipment) in a “serial” manner via the “TxSer”
input pin. Further, the “Receive Payload Data Output Interface” block
will output the “inbound” payload data (to the Terminal Equipment) in a
“serial” manner via the “RxSer” output pin.
T19
Reset
I
Reset Input:
When this "active-low" signal is asserted, the Framer device will be
asynchronously reset. Additionally, all outputs will be "tri-stated", and all
on-chip registers will be reset to their default values.
PIN DESCRIPTION CONNECTED PINS
PIN #PIN NAME
TYPE
DESCRIPTION