
DSP1611/17/18/27/28/29 DIGITAL SIGNAL PROCESSOR
Information Manual
External Memory Interface
April 1998
6-22
DRAFT COPY
Lucent Technologies Inc.
6.4 Timing Examples
(continued)
6.4.6 Write W = 1
illustrates a single write cycle to external data memory with a wait of one. At the beginning of the cycle
(coincident with the falling edge of CKO), ERAMLO goes low enabling the external memory. Then, the address is
placed on the address bus, the data bus is 3-stated by the DSP, and RWN goes low. Halfway through the write
cycle, in this case one CKO period later, the data is placed on the data bus by the DSP. At the end of the write
cycle, ERAMLO goes high allowing the external memory to latch the data. RWN also goes high. The data is left
on the bus for another CKO period to maintain hold time for the external memory.
5-4167
Figure 6-8. Write W = 1
Sample Instructions:
mwait=0x0001
/*
ERAMLO W=1
*/
*r3++=a0
/*
Two-cycle write with W=1, r3 points to ERAMLO
*/
CKO
ERAMLO
DB
RWN
WRITE CYCLE W = 1
AB
ERAMLO ADDRESS
ERAMLO DATA
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...