
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
9-3
9.1 PHIF Operation
(continued)
9.1.1 Intel Mode, 16-Bit Read
The external device drives PCSN, PODS, and PBSEL. The DSP places data on PB for the external device to read.
In the
Intel mode, PIDS is the input data strobe and PODS is the output data strobe with respect to the DSP.
Initially, PB is 3-stated. Valid data is placed on PB if both PCSN (chip select) and PODS (output data strobe) are
low. The timing of this action is initiated 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 PODS 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 PODS or PCSN,
whichever goes high first. PBSEL can now be driven high to select the high byte of pdx0(OUT). The sense of
PBSEL can be reversed by programming the phifc register. The default state is shown here. The cycle is com-
pleted by another strobe from PCSN and PODS. After the high byte is latched into the external device on the rising
edge of PODS, the POBE interrupt is generated and the POBE output pin goes high.
† The logic levels of these pins can be inverted by programming the phifc register.
5-4495
Figure 9-2. Intel Mode, 16-Bit Read
PCSN
(CHIP SELECT)
PODS, FROM
EXTERNAL DEVICE
PB, FROM DSP
POBE
†
PBSEL
†
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...