UPD98404 Datasheet, PDF (13/36 Pages) NEC – ADVANCED ATM SONET FRAMER

µPD98404
1.3 Management interface
Pin name Pin No. I/O level
MSEL
77
TTL*
MADD0-
MADD6
78-84
MD0-MD7 87-94
TTL*
TTL*
CS_B
96
TTL*
DS_B/
97
RD_B
TTL*
R/W_B/
98
WR_B
TTL*
ACK_B/
99
RDY_B
TTL*
PHINT_B
100
TTL*
(1/2)
I/O
Function
I ^{Mode select signal input. The level of input to this pin determines the}
management interface mode.
MSEL = 1: Pin functions RD_B, WR_B, and RDY_B are
selected.
MSEL = 0: Pin functions DS_B, R/W_B, and ACK_B are
selected.
I Address input.
These pins form an address bus to input the address of an internal
register of the µPD98404.
I/O
(3-
state)
8-bit data bus.
These pins form a data bus to read or write data of an internal register
of the µPD98404.
I Chip select signal input. When the signal is low, access to an internal
register is enabled.
I Data strobe signal input or read signal input. This pin functions as
either DS_B or RD_B, depending on the mode selected by the MSEL
pin.
MSEL = 0: This pin functions as DS_B to input the data
strobe signal.
MSEL = 1: This pin functions as RD_B to select read access.
I ^{Read/write signal input or write signal input. This pin functions as}
either R/W_B or WR_B, depending on the mode selected by the
MSEL pin.
MSEL = 0: This pin functions as R/W_B that inputs the
read/write control signal.
High: Read cycle
Low: Write cycle
MSEL = 1: This pin functions as WR_B that selects write access.
O
(3-
state)
Data acknowledge signal output or ready signal output. This pin
functions as either ACK_B or RDY_B, depending on the mode
selected by the MSEL pin.
MSEL = 0 : The pin functions as ACK_B that outputs the data
strobe signal.
MSEL = 1 : The pin functions as RDY_B that selects read access.
O Interrupt signal output.
This pin notifies the host that an internal interrupt source has been
detected. The pin is active low.
Data Sheet S11822EJ4V0DS00
13