Rainbow Electronics DS21458 User Manual

Page 57

DS21455/DS21458 Quad T1/E1/J1 Transceivers

57 of 270

T1CCR1

T1 Common Control Register 1

07h

Bit

# 7 6 5 4 3 2 1 0

Name — — —

TRAI-CI

TAIS-CI

TFM

PDE

TLOOP

Default

0 0 0 0 0 0 0 0

Bit 0/Transmit Loop Code Enable (TLOOP). See Programmable In-Band Loop Codes Generation and Detection for details.

0 = transmit data normally
1 = replace normal transmitted data with repeating code as defined in registers TCD1 and TCD2

Bit 1/Pulse Density Enforcer Enable (PDE). The framer always examines both the transmit and receive data streams for
violations of the following rules, which are required by ANSI T1.403: no more than 15 consecutive zeros and at least N ones
in each and every time window of 8 x (N +1) bits where N = 1 through 23. Violations for the transmit and receive data streams
are reported in the INFO1.6 and INFO1.7 bits respectively. When this bit is set to one, the device will force the transmitted
stream to meet this requirement no matter the content of the transmitted stream. When running B8ZS, this bit should be set to
zero since B8ZS encoded data streams cannot violate the pulse density requirements.

0 = disable transmit pulse density enforcer
1 = enable transmit pulse density enforcer

Bit 2/Transmit Frame Mode Select (TFM).

0 = D4 framing mode
1 = ESF framing mode

Bit 3/Transmit AIS-CI Enable (TAIS-CI). Setting this bit and the TBL bit (T1TCR1.1) causes the AIS-CI code to be
transmitted at TPOSO and TNEGO, as defined in ANSI T1.403.

0 = do not transmit the AIS-CI code
1 = transmit the AIS-CI code (T1TCR1.1 must also be set = 1)

Bit 4/Transmit RAI-CI Enable (TRAI-CI). Setting this bit causes the ESF RAI-CI code to be transmitted in the FDL bit
position.

0 = do not transmit the ESF RAI-CI code
1 = transmit the ESF RAI-CI code

Bit 5/Unused, must be set to zero for proper operation.

Bit 6/Unused, must be set to zero for proper operation.

Bit 7/Unused, must be set to zero for proper operation.