PM7344 S/UNI-MPH
DATA SHEET
PMC-950449
ISSUE 6
MULTI-PHY USER NETWORK INTERFACE
The S/UNI-MPH is configured to select the arbitrary receive interface. ROHI
marks the location of the transmission system overhead bits (TSOH) in the RDD
stream. The active polarity (here shown as active high) of the ROHI signal can
be inverted using the RDNINV bit in the Receive Interface Configuration register.
The active edge that is used to sample RDD and ROHI (here shown as the rising
edge) can be inverted using the RFALL bit in the Receive Interface Configuration
register.
Figure 20
- J2 (6.312 Mbit/s) Transmit Interface
TCOUT
"frame gen
bit count"
JT2F
Outputs
TCG
TTS
TOHO[x]
TDD[x]
S/UNI-MPH
Outputs
TCLKO{x]
The S/UNI-MPH is configured to select the J2 transmit interface. The
connections between the S/UNI-MPH and the JT2F J2 framer should be made
as shown in the "OPERATIONS - Using the JT2F" section. The register bits
TFALL, TOHINV, TRISE, and TDNINV are all set to logic 1 so that TOHI is
sampled on the falling TCLKI edge, TOHI is active low, TDD[x] and TOHO[x] are
updated on the rising edge of TCLKO[x], and TOHO[x] is active low. TOHO[x]
goes low during the first frame alignment bit position in the transmitted data once
every J2 multiframe. The falling edge of TOHO[x] occurs approximately 1 clock
period after TTS gets sampled high (starting at the falling edge of TCOUT where
TTS is sampled high by the S/UNI-MPH and ending at the rising edge of
TCLKO[x] where TOHO[x] is generated). Note that with this configuration,
TCLKO[x] is a flow-through and inverted version of TCOUT whose phase delay
from TCOUT will be less than half a TCOUT period.
PROPRIETARY AND CONFIDENTIAL TO PMC-SIERRA, INC., AND FOR ITS CUSTOMERS’ INTERNAL USE
226
PMC [ PMC-SIERRA, INC ]
