MC145574AAC Freescale Semiconductor, MC145574AAC Datasheet - Page 87

• Manufacturer Part Number: MC145574AAC
• Description: IC TRANSCEIVER ISDN 32-LQFP
• Manufacturer: Freescale Semiconductor
• Type: Transceiverr

Specifications of MC145574AAC

• Voltage - Supply: 4.75 V ~ 5.25 V
• Mounting Type: Surface Mount
• Package / Case: 32-LQFP
• Number Of Line Interfaces: 1
• Control Interface: HDLC
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Number Of Drivers/receivers: -
• Protocol: -
• Lead Free Status / Rohs Status: Compliant

MOTOROLA
BR11(5), BR11(4) — Rx INFO State B1 and B0
These bits are read/write bits and are applicable to both NT and TE modes of operation. The MC145574
internally sets these bits to indicate the status of the received signal; i.e., it is INFO 0, 1, 2, 3, 4, or
X, where INFO X is none of the above. An example of INFO X would be when it is receiving the 96 kHz
test signal. Another example of INFO X would be where the transceiver is not receiving INFO 0, but
it has not yet determined whether it is INFO 1, 2, 3, or 4.
The codes corresponding to the different states are shown in Table 9–5.
NOTE: When configured as an NT, receiving INFO LOW corresponds to receiving INFO 1, and receiv-
ing INFO HIGH corresponds to receiving INFO 3. Conversely, when the device is operating as a TE,
receiving INFO LOW corresponds to receiving INFO 2, and receiving INFO HIGH corresponds to re-
ceiving INFO 4. The device internally sets these bits, and this internal write overrides any external
write. These bits are reset to 0 by application of either a hardware or software reset.
BR11(3), BR11(2) — Tx INFO State B1 and B0
These bits are read/write bits and are applicable to both NT and TE modes of operation. The MC145574
internally sets these bits to indicate the status of the transmitted signal; i.e., is it INFO 0, 1, 2, 3, 4,
or X where INFO X is none of the above. An example of INFO X would be when it is transmitting
the 96 kHz test signal. The codes corresponding to the different states is shown in Table 9–6.
NOTE: When configured as an NT, transmitting INFO LOW corresponds to transmitting INFO 2, and
transmitting INFO HIGH corresponds to transmitting INFO 4. Conversely, when the device is operating
as a TE, transmitting INFO LOW corresponds to transmitting INFO 1, and transmitting INFO HIGH
corresponds to transmitting INFO 3. The device internally sets these bits, and this internal write over-
rides any external write. These bits are reset to 0 by application of either a hardware or software reset.
BR11(1) — External S/T Loopback
This bit is a read/write bit and is applicable to both NT and TE modes of operation. When this bit
is 0, the MC145574 functions normally. If the transmit pair is shorted to the receive pair while this
bit is 1, the device will perform an external or “analog” loopback. In an analog loopback, the device
demodulates its own transmitted data. The transceiver should have its activation procedures disabled
(BR7(7) = 1) and be configured for the IDL2 master mode (BR7(3) = 1). This feature is useful for
test purposes. In external loopback, the B1 and B2 channels are looped back. In the NT mode, the
D channel is also looped back. The D channel is not looped back in the TE mode. Application of a
hardware or software reset will reset this bit to 0.
Freescale Semiconductor, Inc.
For More Information On This Product,
Table 9–5. BR11(5), BR11(4) Rx INFO State Codes
Table 9–6. BR11(3), BR11(2) Tx INFO State Codes
BR11(5)
BR11(3)
0
0
1
1
0
0
1
1
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MC145574
BR11(4)
BR11(2)
0
1
0
1
0
1
0
1
Transmit Information State
Receive Information State
INFO HIGH
INFO HIGH
INFO LOW
INFO LOW
INFO X
INFO X
INFO 0
INFO 0
9–11