LSI Logic Confidential
Async Slave WRITE and READ Protocols
8-7
Copyright © 2001, 2002 by LSI Logic Corporation. All rights reserved.
•
The processor deasserts DTACK (6) also in response to RD
deassertion.
Figure 8.3
I-Mode READ
8.3.4
M-Mode WRITE and READ Operations
To select M-mode, the Host performs a dummy write cycle to the Host
Address Register (address 0x4) with the CS strobe asserted after WR in
the first Host access after reset. The RD pin is held HIGH throughout
M-mode.
In M-mode, the address is sampled when WAIT and DTACK are driven
when CS goes LOW.
8.3.5
M-Mode Incoming Transfers
shows an M-mode write. The sequence is as follows:
•
The Host drives the address and WR and asserts CS (1) after the
address and WR (2) are stable.
•
The DMN-8600 processor asserts WAIT and deasserts DTACK (3)
in response to a CS HIGH-to-LOW edge.
•
The processor then deasserts WAIT (4) and asserts DTACK when it
is ready to take data in.
•
The Host deasserts CS (5) in response to either the WAIT
deassertion or DTACK assertion.
CS (I)
RD (I)
WAIT (O)
DTACK (O)
A[2:0] (I)
D[31:0] (I/O)
3
4
2
1
Address
Data
6
2
5
3
Содержание DMN-8600
Страница 14: ...LSI Logic Confidential xiv Contents Copyright 2001 2002 by LSI Logic Corporation All rights reserved ...
Страница 18: ...LSI Logic Confidential xviii Copyright 2001 2002 by LSI Logic Corporation All rights reserved ...
Страница 64: ...LSI Logic Confidential 7 6 Memory Mapping Copyright 2001 2002 by LSI Logic Corporation All rights reserved ...