DS2154 Dallas Semiconducotr, DS2154 Datasheet - Page 60

• Manufacturer Part Number: DS2154
• Description: Enhanced E1 Single Chip Transceiver
• Manufacturer: Dallas Semiconducotr

11.3 INTERNAL REGISTER SCHEME BASED ON CRC4 MULTIFRAME
On the receive side, there is a set of eight registers (RSiAF, RSiNAF, RRA, RSa4 to RSa8) that report the
Si and Sa bits as they are received. These registers are updated with the setting of the Receive CRC4
Multiframe bit in Status Register 2 (SR2.1). The host can use the SR2.1 bit to know when to read these
registers. The user has 2 ms to retrieve the data before it is lost. The MSB of each register is the first
received. Please see the register descriptions below and the Transmit Data Flow diagram in Section 13 for
more details.
On the transmit side, there is also a set of eight registers (TSiAF, TSiNAF, TRA, TSa4 to TSa8) that can
be programmed to insert both Si and Sa data via the Transmit Sa Bit Control Register (TSaCR). Data is
sampled from these registers with the setting of the Transmit Multiframe bit in Status Register 2 (SR2.5).
The host can use the SR2.5 bit to know when to update these registers. It has 2 ms to update the data or
else the old data will be retransmitted. The MSB of each register is the first bit transmitted. Please see the
register descriptions below and the Transmit Data Flow diagram in Section 13 for more details.
REGISTER
RSiNAF
TSiNAF
NAME
RSiAF
TSiAF
RSa4
RSa5
RSa6
RSa7
RSa8
TSa4
TSa5
TSa6
TSa7
TSa8
RRA
TRA
ADDRESS
(HEX)
5A
5D
5B
5C
5E
59
5F
58
50
51
52
53
54
55
56
57
The 8 Si bits in the align frame
The 8 Si bits in the non-align frame
The 8 reportings of the receive remote alarm (RA)
The 8 Sa4 reported in each CRC4 multiframe
The 8 Sa5 reported in each CRC4 multiframe
The 8 Sa6 reported in each CRC4 multiframe
The 8 Sa7 reported in each CRC4 multiframe
The eight Sa8 reported in each CRC4 multiframe
The 8 Si bits to be inserted into the align frame
The 8 Si bits to be inserted into the non-align frame
The 8 settings of remote alarm (RA)
The 8 Sa4 settings in each CRC4 multiframe
The 8 Sa5 settings in each CRC4 multiframe
The 8 Sa6 settings in each CRC4 multiframe
The 8 Sa7 settings in each CRC4 multiframe
The 8 Sa8 settings in each CRC4 multiframe
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FUNCTION
DS2154