TMP92CF30
2009-06-12
92CF30-188
(b) Subroutine (Bank 0 in LOCAL-Y)
Logical
address
Physical
address
Instruction
No.
Instruction Comment
16
org 400000H
;
400000H
000000H
17
ldw (localrz), 8001H
; Bank 0 in LOCAL-Z is configured as
read-data memory for Character-RAM
4000xxH
0000xxH
18
ld xiy,800000H
; Index address register for reading
Character-ROM
19
ld wa,(xiy)
; Read Character-ROM
20
:
;
21
ld (localpy), 82H
;
22
:
5000yyH
1000yyH
23
ret
;
•
The instruction No.17 configures Bank 0 of the LOCAL-Z area to read data from
character-ROM.
•
The instructions No.18 and No.19 are used to read data from character-ROM. When the
CPU generates the address 800000H, the MMU translates it to the physical address
000000H, which is then placed onto the external address bus: A23 to A0. Since the logical
address is within the address range of the CS2 space,
CSZA
for NOR-Flash is asserted at
the same time. By using these instructions, the CPU can read data from character ROM.
•
The instruction No.21 switches the program bank in the LOCAL area. Since the program
bank switching within the same LOCAL area is prohibited, this is a bad example.
Summary of Contents for TLCS-900/H1 Series
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