![](http://datasheet.mmic.net.cn/330000/PM73487-PI_datasheet_16444394/PM73487-PI_84.png)
PM73487 QRT
PMC-Sierra, Inc.
PMC-980618
Issue 3
622 Mbps ATMTraffic Management Device
Released
Datasheet
72
4.3.9
UTOPIA ATM Layer Interface Signals
4.3.9.1
Transmit UTOPIA ATM Layer Interface Signals
4.3.9.2
Receive UTOPIA ATM Layer Interface Signals
Table 16. Transmit UTOPIA ATM Layer Interface Signals (29 Pins)
Signal Name
Ball
Type
Drive/Input
Level
Slew
Rate
Description
ATM_CLK
V27
In
CMOS
UTOPIA ATM Layer Clock
provides
timing information for both the transmit
and receive UTOPIA interfaces.
TATM_ADD(4:0)
AH19, AG17, AF18,
AJ17, AG18
Out
12 ma
Mod
Transmit UTOPIA ATM Layer Address
Bits 4 to 0
.
TATM_DATA(15:0)
AH17, AH16, AF16,
AG16, AE16, AH15,
AE15, AF15, AG15, AJ13,
AH13, AH14, AG13,
AG14, AF13, AH12
Out
12 ma
Mod
Transmit UTOPIA ATM Layer Data
Bits 15 to 0
are part of the 16-bit UTO-
PIA transmit data bus that carries data
toward the PHY layer device.
TATM_CLAV(3:0)
AH11, AF14, AG12, AF12
In
5 V or
LV TTL
Transmit UTOPIA ATM Layer Cell
Available
Bits 3 to 0
are active high sig-
nals that indicate the selected PHY
layer devices may accept another cell.
TATM_SOC
AE12
Out
12 ma
Mod
Transmit UTOPIA ATM Layer Start-
Of-Cell
marks the start of a cell.
/TATM_WRITE_EN
AE14
Out
12 ma
Mod
Transmit UTOPIA ATM Layer Write
Enable
enables the write of a cell byte.
TATM_PARITY
AE13
Out
12 ma
Mod
Transmit UTOPIA ATM Layer Odd
Parity
bit over TATM_DATA(15:0).
Table 17. Receive UTOPIA ATM Layer Interface Signals (27 Pins)
Signal Name
Ball
Type
Drive/
Input Level
Slew
Rate
Description
RATM_ADD(4:0)
C19, C21, B21, E20,
D19
Out
12 ma
Mod
Receive UTOPIA ATM Layer Address
Bits 4 to 0
RATM_DATA(15:0)
D15, A17, B17, C17,
B18, D17, C16, B20,
B19, D16, D18, C18,
E18, E16, E17, B22
In
5V or LV
TTL
Receive UTOPIA ATM Layer Data Bits
15 to 0 are
part of the 16-bit UTOPIA
receive data bus that carries data from
the PHY layer device.
RATM_SOC
D21
In
5V or LV
TTL
Receive UTOPIA ATM Layer Start-Of-
Cell
marks the start of a cell.
RATM_CLAV(3:0)
C22, E19, A24, D20
In
5V or LV
TTL
Receive UTOPIA ATM Layer Cell
Available Bits 0 to
3 indicate the
selected PHY layer devices have
another cell.
/RATM_READ_EN
C20
Out
12 ma
Mod
Receive UTOPIA ATM Layer Read
Enable
causes a read from the FIFO in
the PHY layer device.