PM6341 E1XC
DATA SHEET
PMC-910419
ISSUE 8
E1 FRAMER/TRANSCEIVER
Register 28H: FRMR International/National Bits
Bit
Type
Function
Default
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
R
R
R
R
R
R
R
R
Si1
Si0
X
X
X
X
X
X
X
X
RAWRA
Sn0
Sn1
Sn2
Sn3
Sn4
Reading this register returns the current bit value of the International and
National bits collected over 2 consecutive frames.The Si1 bit position
corresponds to the value contained in the International bit position in the FAS
frame; the Si0, RAWRA, and Sn[4:0] bit positions correspond to the values
contained in the International, Remote Alarm Indication, and National bit
positions in the NFAS frame.This register is updated after time slot 0 of every
NFAS frame and the contents are valid for 2 frames (250µs).The contents of this
register are latched during the read, however the individual bits should not be
considered to constitute a byte value (i.e. the 5 national bits should not be
considered as indicating 1 of 32 possible values since it is possible that the
individual bits are not all from the same time instant due to the asynchronous
nature of the microprocessor reads). If the bits are to be interpreted as binary
values, care should be taken to ensure a coherent set of bit values by reading
the register at least twice.
The Si0, RAWRA and Sn0-Sn4 bits map to the TSO NFAS as follows:
Bit Position
1
2
3
4
5
6
7
8
RAWRA
Si0
1
Sn0
Sn1
Sn2
Sn3
Sn4
Note that the TXSAEN[8:4] bits in the E1XC Transmit Framing Options Register
(Register 06H) can cause a datalink to overwrite some or all of the National Use
Bits.
PROPRIETARY AND CONFIDENTIAL TO PMC-SIERRA, INC., AND FOR ITS CUSTOMERS’ INTERNAL USE
133
PMC [ PMC-SIERRA, INC ]
