Information Manual
DSP1611/17/18/27/28/29 DIGITAL SIGNAL PROCESSOR
April 1998
Serial I/O
Lucent Technologies Inc.
DRAFT COPY
7-21
7.6 Multiprocessor Mode Description
(continued)
7.6.2 Detailed Multiprocessor Mode Description (continued)
If the serial transmit address coming from the bidirectional ADD line of the transmitting device matches the receive
address of one of the other devices, the data input is loaded into that device's input buffer and its IBF flag is set at
the end of the transmission. The source ID or protocol information (
[7:0]) of the transmitting device is also
loaded into the saddx register as described above. In order to read in the new data and source ID, an interrupt can
take place based on the IBF flag. The transmit address is 8 bits wide with eight DSP devices (maximum) in the
multiprocessor configuration. This means there is one address bit per DSP device. The srta register has one
address bit per device in order to allow transmissions to more than one device at a time. A broadcast mode send-
ing data from one device to all others is accomplished by setting all bits high in the transmission field of srta.
Typically, the time-division multiplex slot register (tdms) is set up at the beginning of a program and does not
change for each of the devices in the multiprocessor system. If the time slot needs to be changed, it is imperative
that each processor still have its own unique time slot. All new time slots are updated at the end
of each time
slot 0 (refer to
).
During reset, the tdms register clears to all zeros disabling multiprocessor mode by default. The srta register is
unaltered by reset.
If a DSP has been set up to transmit in some particular time slot and the software running in that DSP fails to write
the sdx register in preparation for that transmission, that DSP will drive the ADD line to all ones (inactive) for that
entire time slot. This prevents spurious interrupts from occurring in what would have been the destination DSP(s)
for that time slot if data had been available. In this way, the destination DSP(s) need only act on information sent by
the source DSP if it actually has new data available. Once the data becomes available, the transmission will wait
until the next available time slot.
Table 7-6. Serial Receive/Transmit Address (srta) Register
Bit
15—8
7—0
Field
RECEIVE ADDRESS
TRANSMIT ADDRESS
Field
Value
Result/Description
RECEIVE ADDRESS
1xxxxxxx
Receive address 7.
x1xxxxxx
Receive address 6.
xx1xxxxx
Receive address 5.
xxx1xxxx
Receive address 4.
xxxx1xxx
Receive address 3.
xxxxx1xx
Receive address 2.
xxxxxx1x
Receive address 1.
xxxxxxx1
Receive address 0.
TRANSMIT ADDRESS
1xxxxxxx
Transmit address 7.
x1xxxxxx
Transmit address 6.
xx1xxxxx
Transmit address 5.
xxx1xxxx
Transmit address 4.
xxxx1xxx
Transmit address 3.
xxxxx1xx
Transmit address 2.
xxxxxx1x
Transmit address 1.
xxxxxxx1
Transmit address 0.
AS
Содержание DSP1611
Страница 18: ...Chapter 1 Introduction...
Страница 27: ...Chapter 2 Hardware Architecture...
Страница 52: ...Chapter 3 Software Architecture...
Страница 116: ...Chapter 4 Instruction Set...
Страница 154: ...Chapter 5 Core Architecture...
Страница 176: ...Chapter 6 External Memory Interface...
Страница 208: ...Chapter 7 Serial I O...
Страница 237: ...Chapter 8 Parallel I O DSP1617 Only...
Страница 261: ...Chapter 9 Parallel Host Interface PHIF DSP1611 18 27 28 29 Only...
Страница 275: ...Chapter 10 Bit I O Unit...
Страница 284: ...Chapter 11 JTAG Test Access Port...
Страница 306: ...Chapter 12 Timer...
Страница 313: ...Chapter 13 Bit Manipulation Unit...
Страница 325: ...Chapter 14 Error Correction Coprocessor DSP1618 28 Only...
Страница 350: ...Chapter 15 Interface Guide...
Страница 367: ...Appendix A Instruction Encoding...
Страница 379: ...Appendix B Instruction Set Summary...
Страница 381: ...aD extractz aS IM16 B 52 aD insert aS arM B 53 aD insert aS IM16 B 54 aD aS aaT B 55...
Страница 437: ...Index...