Table 7-5. Time-Division Multiplex Slot (Tdms) Register - Lucent Technologies DSP1617 Information Manual

DSP1611/17/18/27/28/29 DIGITAL SIGNAL PROCESSOR
Serial I/O
7.6 Multiprocessor Mode Description
7.6.2 Detailed Multiprocessor Mode Description (continued)
The protocol information is made available in the high byte of saddx to allow branching on the top bit without
requiring any shift or compare operations. The low byte of saddx is always zero on a read. Two distinct registers
are actually accessed if reading and writing the saddx register; writes go to the register holding the transmitted
value, and reads get the received value from the receiving register. This is similar to the operation of the sdx regis-
ter.
This 8-bit protocol can be any value and constitutes an independent 8-bit serial channel while in multiprocessor
mode. It is targeted to the destination DSP(s) along with the data and can be used for any desired purpose. For
example, the top 3 bits of the saddx value is sufficient to encode a source ID for each source DSP (up to eight
maximum on the TDM bus) leaving the remaining 5 bits free to convey other information about the associated data
such as opcode/data bits, first/last word in transmission, or parity.

Table 7-5. Time-Division Multiplex Slot (tdms) Register

Bit
9 8
Field SYNCSP MODE
Field
SYNCSP
MODE
TRANSMIT SLOT
SYNC
† See sioc register, LD field in
‡ Select this mode if in multiprocessor mode.
7-20
(continued)
Value
0 SYNC = ICK/OCK
1 SYNC = ICK/OCK
0 Multiprocessor mode off. DOEN is an input (passive mode).
1 Multiprocessor mode on. DOEN is an output (active mode).
1xxxxxxx Transmit slot 7.
x1xxxxxx Transmit slot 6.
xx1xxxxx Transmit slot 5.
xxx1xxxx Transmit slot 4.
xxxx1xxx Transmit slot 3.
xxxxx1xx Transmit slot 2.
xxxxxx1x Transmit slot 1.
1 Transmit slot 0. SYNC is an output (active mode).
0 SYNC is an input (passive mode).
Table 7-1.
DRAFT COPY
7—1
TRANSMIT SLOT
Result/Description
†
÷ 128.
‡
÷ 256.
†
Information Manual
April 1998
0
SYNC
Lucent Technologies Inc.