STANDARD PRODUCT
PM4351 COMET
DATA SHEET
PMC-1970624
ISSUE 10
COMBINED E1/T1 TRANSCEIVER
logic 0, the bipolar TXTIP and TXRING outputs are forced to pulse alternately
every other cycle; when TAUXP and TUNI are both set to logic 1, the unipolar
TDAT output is forced to toggle every cycle. The transition to transmitting
AUXP on the TXTIP and TXRING outputs is done in such a way as to not
introduce any bipolar violations.
The diagnostic loopback point is upstream of this AUXP insertion point.
TDATINV:
The TDATINV bit enables the digital transmit interface to logically invert the
TDAT signal. When TDATINV is set to logic 1, the TDAT output is active low.
When TDATINV is set to logic 0, the TDAT output is active high.
TDATINV only has effect when TUNI is a logic 1.
TUNI:
The TUNI bit determines which interface presents the transmit data.
If TUNI is a logic 1, the transmit data is presented as TTL compatible unipolar
data on the TDAT output with an associated clock on the TCLKO output and
frame alignment pulse on the TFP output. The transmit line interface is held
reset; therefore, the TXTIP and TXRING outputs are high-impedance.
If TUNI is a logic 0, the transmit data is presented on the TXTIP and TXRING
as pulses suitable for driving a transformer directly and the TDAT, TFP and
TCLKO outputs are held low.
TRISE:
When TRISE is set to logic 1, the interface is enabled to update the TDAT
and TFP output pins on the rising edge of TCLKO. When TRISE is set to
logic 0, the interface is enabled to update the outputs on the falling edge of
TCLKO.
PROPRIETARY AND CONFIDENTIAL
86
PMC [ PMC-SIERRA, INC ]
