DS21354/DS21554 3.3V/5V E1 Single-Chip Transceivers
TNAF: TRANSMIT NON-ALIGN FRAME REGISTER (Address = 21 Hex)
(MSB)
(LSB)
Si
1
A
Sa4
Sa5
Sa6
Sa7
Sa8
SYMBOL POSITION
NAME AND DESCRIPTION
Si
1
TNAF.7
TNAF.6
TNAF.5
TNAF.4
TNAF.3
TNAF.2
TNAF.1
TNAF.0
International Bit.
Frame Non-Alignment Signal Bit.
Remote Alarm (used to transmit the alarm).
Additional Bit 4.
A
Sa4
Sa5
Sa6
Sa7
Sa8
Additional Bit 5.
Additional Bit 6.
Additional Bit 7.
Additional Bit 8.
Note: Bit 6 of the TNAF register must be programmed to one. The DS21354/DS21554 do not
automatically set this bit.
13.3. 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 2ms to retrieve the data before it is lost. The MSB of each register is the first
received. Please see the register descriptions below for more details.
On the transmit side, there is also a set of eight registers (TSiAF, TSiNAF, TRA, TSa4 to TSa8) that via
the Transmit Sa-Bit Control Register (TSaCR), can be programmed to insert both Si and Sa data. 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 2ms 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 Figure 18-15 for more details.
REGISTER
RSiAF
RSiNAF
RRA
ADDRESS (HEX)
FUNCTION
58
59
5A
5B
5C
5D
5E
5F
50
51
52
53
54
55
56
57
The eight Si bits in the align frame
The eight Si bits in the non-align frame
The eight reportings of the receive remote alarm (RA)
The eight Sa4 reported in each CRC4 multiframe
The eight Sa5 reported in each CRC4 multiframe
The eight Sa6 reported in each CRC4 multiframe
The eight Sa7 reported in each CRC4 multiframe
The eight Sa8 reported in each CRC4 multiframe
The eight Si bits to be inserted into the align frame
The eight Si bits to be inserted into the non-align frame
The eight settings of remote alarm (RA)
RSa4
RSa5
RSa6
RSa7
RSa8
TSiAF
TSiNAF
TRA
TSa4
The eight Sa4 settings in each CRC4 multiframe
The eight Sa5 settings in each CRC4 multiframe
The eight Sa6 settings in each CRC4 multiframe
The eight Sa7 settings in each CRC4 multiframe
The eight Sa8 settings in each CRC4 multiframe
TSa5
TSa6
TSa7
TSa8
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