TMP91C824
91C824-117
2008-02-20
At Figure 3.8.3, it shows example of connection TMP91C824 and some memories:
Program ROM: MROM, 16 Mbytes, data ROM: MROM, 64 Mbytes, data RAM: SRAM, 8
Mbytes, 8-bit bus, option ROM: Flash, 16 Mbytes.
In case of 16-bit bus memory connection, it need to shift 1-bit address bus from
TMP91C824 and 8-bit bus case, direct connection address bus from TMP91C824.
In that figure, logical address and physical address are shown. And each memory allot
each chip select signal, RAM:
CS0
,
FLASH
ROM:
CS1
, program MROM:
CS2
, data
MROM:
CS3
. In case of this example, as data MROM is 64 Mbytes, this MROM connect to
EA24 and EA25.
Initial condition after reset, because TMP91C824 access from
CS2
area,
CS2
area allot
to program ROM. It can set free setting except program ROM.
;Initial Setting
;CS0
LD
(MSAR0),00H
; Logical address area: 000000H to 1FFFFFH
LD
(MAMR0),FFH ; Logical address size: 2 Mbytes
LD
(B0CS),89H
; Condition: 8 bits, 1 wait (8 Mbytes, SRAM)
;CS1
LD
(MSAR1),40H
; Logical address area: 400000H to 7FFFFFH
LD
(MAMR1),FFH ; Logical address size: 4 Mbytes
LD
(B1CS),80H
; Condition: 16 bits, 2 waits (16 Mbytes, Flash ROM)
;CS2
LD
(MSAR2),C0H ; Logical address area: C00000H to FFFFFFH
LD
(MAMR2),7FH ; Logical address size: 4 Mbytes
LD
(B2CS),C3H
; Condition: 16 bits, 0 waits (16 Mbytes, MROM)
;CS3
LD
(MSAR3),80H
; Logical address area: 800000H to BFFFFFH
LD
(MAMR3),7FH ; Logical address size: 4 Mbytes
LD
(B3CS),85H
; Condition: 16 bits, 3 waits (64 Mbytes, MROM)
;CSX
LD
(BEXCS),00H
; Other : 16 bits, 2 waits (Don’t care)
;Port
LD (P6FC),
3FH ;
CS0
to
CS3
, EA24, EA25: Port 6 setting
Figure 3.8.4 BANK Operation S/W Example 1
Secondly, it shows example of initial setting at Figure 3.8.4.
Because
CS0
connect to RAM: 8-bit bus, 8 Mbytes, it need to set 8-bit bus. At this
example, it set 1-wait setting. In the same way
CS1
set to 16-bit bus and 2 waits,
CS2
set
16-bit bus and 0 waits,
CS3
set 16-bit bus and 3 waits.
By CS/WAIT controller, each chip selection signal’s memory size, don’t set actual
connect memory size, need to set that logical address size: fitting to each local area. Actual
physical address is set by each area’s BANK register setting.
CSX setting of CS/WAIT controller is except above CS0 to CS3’s setting. This program
example isn’t used CSX setting.
Finally pin condition is set. Port 60 to 65 set to
CS0
,
CS1
,
CS2
,
CS3
, EA24, EA25.