Table of Contents
Advertisement
(6) Procedure for setting chip select/wait control
When using the chip select/wait control function, set the registers in the following
order:
1.
Set the memory start address registers MSAR0 to MSAR3.
Set the start addresses for CS0 to CS3.
2.
Set the memory address mask registers MAMR0 to MAMR3.
Set the sizes of CS0 to CS3.
3.
Set the chip select/wait control registers B0CS to B3CS.
Set the chip select output waveform, data bus width, number of waits and
master enable/disable status for
The CS0 to CS3 pins can also function as pins P60 to P63. To output a chip
select signal using one of these pins, set the corresponding bit in the port 6
function register P6FC to 1.
If a CS0 to CS3 address is specified which is actually an internal I/O and RAM
area address, the CPU accesses the internal address area and no chip select
signal is output on any of the
Setting example:
In this example CS0 is set to be the 64-Kbyte area 010000H to 01FFFFH. The bus
width is set to 16 bits and the number of waits is set to 0.
MSAR0 = 01H
Start address: 010000H
MAMR0 = 07H
Address area: 64 Kbytes
B0CS = 83H
ROM/SRAM, 16-bit data bus, 0 waits, CS0 area settings enabled.
to
.
CS0
CS3
to
pins.
CS0
CS3
91C824-88
TMP91C824
2008-02-20
Advertisement
Table of Contents
