XRT7250 Datasheet, PDF (23/463 Pages) Exar Corporation – DS3/E3 FRAMER IC

XRT7250 DS3/E3 FRAMER IC
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REV. 1.1.1
PIN DESCRIPTION
PIN #
10
NAME
RD_DS
11
NC
12
NC
13
INT
14
GND
15
A0
16
A1
17
A2
18
A3
19
A4
20
A5
21
A6
22
A7
23
A8
24
VDD
TYPE
DESCRIPTION
I Read Data Strobe (Intel Mode)
If the microprocessor interface is operating in the Intel Mode, then this input will
function as the RD (READ STROBE) input signal from the local µP. Once this
active-low signal is asserted, then the Framer will place the contents of the
addressed registers (within the Framer) on the Microprocessor Data Bus
(D[7:0]). When this signal is negated, the Data Bus will be tri-stated.
Data Strobe (Motorola Mode):
If the microprocessor interface is operating in the Motorola mode, then this pin
will function as the active-low Data Strobe signal.
Not Bonded Out
Not Bonded Out
O Interrupt Request Output:
This open-drain, active-low output signal will be asserted when the Framer
device is requesting interrupt service from the local microprocessor. This out-
put pin should typically be connected to the "Interrupt Request" input of the
local microprocessor.
Ground Pin
I Address Bus Input (Microprocessor Interface) - LSB (Least Signif-
icant Bit)
(Please see description for A8)
I Address Bus Input (Microprocessor Interface):
(Please see description for A8)
I Address Bus Input (Microprocessor Interface):
(Please see description for A8)
I Address Bus Input (Microprocessor Interface):
(Please see description for A8)
I Address Bus Input (Microprocessor Interface):
(Please see description for A8)
I Address Bus Input (Microprocessor Interface):
(Please see description for A8)
I Address Bus Input (Microprocessor Interface):
(Please see description for A8)
I Address Bus Input (Microprocessor Interface):
(Please see description for A8)
I Address Bus Input (Microprocessor Interface) - MSB (Most Signif-
icant Bit):
This input pin, along with inputs A0 - A7 are used to select the on-chip Framer
register and RAM space for READ/WRITE operations with the "local" micropro-
cessor.
**** Power Supply Pin
4