Information Manual
DSP1611/17/18/27/28/29 DIGITAL SIGNAL PROCESSOR
April 1998
Parallel Host Interface (PHIF) (DSP1611/18/27/28/29 Only)
Lucent Technologies Inc.
DRAFT COPY
9-5
9.1 PHIF Operation
(continued)
9.1.3 Motorola Mode, 16-Bit Read
The external device drives PCSN, PRWN, PODS/PDS, and PIDS/PBSEL. The DSP drives PB.
In
Motorola mode, PIDS is renamed PRWN (parallel read/write not) and selects a read or a write. PODS is
renamed PDS and is the data strobe for both input and output.
Initially, PB is 3-stated. The read operation is selected if PRWN is high during the transaction. Valid data is placed
on PB if both PCSN (chip select) and PDS (input data strobe) are low. The timing of this action is controlled by
whichever of the two goes low last. PBSEL (byte-select) is low, so the low byte from the pdx0(OUT) register is
placed on PB. If PDS is driven high by the external device, the data is latched externally and the DSP can again 3-
state the PB. The timing of this action is controlled by PDS or PCSN, whichever goes high first. PBSEL can now
be driven high to select the high byte of pdx0(OUT). The sense of PBSEL and PDS can be reversed by program-
ming the phifc register. The default state is shown here. The cycle is completed by another strobe from PCSN
and PDS. After the rising edge of PDS latches the high byte into the external device, the POBE interrupt is gener-
ated and the POBE output pin goes high.
† The logic levels of these pins can be inverted by programming the phifc register.
5-4497
Figure 9-4. Motorola Mode, 16-Bit Read
PCSN
PIDS/PRWN
(CHIP SELECT)
PODS/PDS
†
, FROM
EXTERNAL DEVICE
PB, FROM DSP
POBE
†
PBSE
LOW BYTE READ
HIGH BYTE READ
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...