mt9074ap1 Zarlink Semiconductor, mt9074ap1 Datasheet - Page 33

• Manufacturer Part Number: mt9074ap1
• Description: T1/e1/j1 Single Chip Transceiver With Wide Dynamic Range Liu
• Manufacturer: Zarlink Semiconductor

MT9074
Data Sheet
Identification Code
The MT9074 shall be identified by the code 10101111, read from the identification code status register (page 03H,
address 1FH).
ST-BUS Streams
In T1 mode, there is one control and one status ST-BUS stream that can be used to program / access channel
associated signaling nibbles. CSTo contains the received channel associated signaling bits, and for those channels
whose Per Time Slot Control word bit 1 "RPSIG" is set low, CSTi is used to control the transmit channel associated
signaling. The DSTi and DSTo streams contain the transmit and receive voice and digital data. Only 24 of the 32
ST-BUS channels are used for each of DSTi, DSTo, CSTi and CSTo. In each case individual channel mapping is as
illustrated in Table 6, “STBUS vs. DS1 to Channel Relationship(T1),” on page 26.
In E1 mode, the ST-BUS stream can also be used to access channel associated signaling nibbles. CSTo contains
the received channel associated signaling bits (e.g., ITU-T R1 and R2 signaling), and for those channels whose Per
Time Slot Control word bit 1 "RPSIG" is set low, CSTi is used to control the transmit channel associated signaling.
The DSTi and DSTo streams contain the transmit and receive voice and digital data.
Only 30 of the 32 ST-BUS channels are used for each of DSTi, DSTo, CSTi and CSTo. In each case individual
channel mapping is as illustrated in Table 10 Time slot to Channel Relationship.
Reset Operation (Initialization)
The MT9074 can be reset using the hardware RESET pin (see pin description for external reset circuit
requirements) for T1 and (pin 11 in PLCC, pin 84 in MQFP) or the software reset bit RST (page 1H, address 1AH)
for E1/T1.
NOTE: Following a software reset, the device may insert bipolar violations in the transmit data stream
output on TTIP and TRING. This condition occurs infrequently upon software reset. Once the error
condition exists, it will continue indefinitely until the device is reset.
To obtain error free data transmission, it is recommended that a software routine execute upon software
reset. This routine loops back the analog signal. If bipolar violations occur, the device must be reset, and
the procedure is repeated.
This routine shall execute as follows:
(1) Set all registers as per desired operating mode.
(2) Place the device into metallic loopback (set bit 6 address 15H of page 1, in T1 mode - 7.5 dB of line build
out will also have to be programmed).
(3) Wait until frame synchronization is achieved.
(4) Clear the Bipolar Violation counters.
(5) Wait 100 milliseconds.
(6) Check for bipolar violation errors. If any occur reset the device and return to step (1).
33
Zarlink Semiconductor Inc.