MT90401 Zarlink Semiconductor, MT90401 Datasheet - Page 6

• Manufacturer Part Number: MT90401
• Description: Sonet/sdh System Synchronizer
• Manufacturer: Zarlink Semiconductor

Pin Description (continued)
66-69
74-77
Pin #
63
64
65
70
71
72
73
78
79
80
D0 - D3
D4 - D7
Name
V
V
RST
R/W
HW
CS
A0
IC
IC
IC
SS8
DD5
Chip Select (5V tolerant Input). This active low input enables the non-multiplexed
Motorola parallel microprocessor interface of the MT90401. When CS is set to high, the
microprocessor interface is idle and all bus I/O pins will be in a high impedance state.
RESET (5V tolerant Input). This active low input puts the MT90401 in a reset condition.
RST should be set to high for normal operation. The MT90401 should be reset after power-
up and after the selected reference frequency is changed. The RST pin must be held low for
a minimum of 1 sec. to reset the device properly.
Hardware Mode (Input). If this pin is tied low, the device is in microport mode and is
controlled via the microport. If it is tied high, the device is in hardware mode and is
controlled via the control pins MS1, MS2, FS1, FS2, FLOCK and SONET/SDH.
Data 0 to Data 3 (5V tolerant Three-state I/O). These signals combined with D4-D7 form
the bidirectional data bus of the parallel processor interface (D0 is the least significant bit).
Digital ground. 0 Volts.
Internal Connection. Tie low for normal operation.
Internal Connection. Tie low for normal operation.
Positive Power Supply. Digital supply.
Data 4 to Data 7 (5V tolerant Three-state I/O). These signals combined with D0-D3 form
the bidirectional data bus of the parallel processor interface (D7 is the most significant bit).
Read/Write Select (5V tolerant Input). This input controls the direction of the data bus
D[0:7] during a microprocessor access. When R/W is high, the parallel processor is reading
data from the MT90401. When low, the parallel processor is writing data to the MT90401.
Address 0 (5V tolerant Input). Address input for the parallel processor interface. A0 is the
least significant input.
Internal Connection. Tie low for normal operation.
Zarlink Semiconductor Inc.
MT90401
6
Description
Data Sheet