Toshiba TLCS-900/H1 Series Data Book page 146

(c) Sub routine (Bank-0 in LOCAL-Y)
Logical Physical
address address
400000H 000000H
4000xxH 0000xxH
5000yyH 1000yyH
・No.17 and No.18 are setting for Bank-1 of LOCAL-Y. In this case, LCD Display data is written to SRAM by CPU.
So, (LOCALWY) and (LOCALLY) should be set to same bank-1.
・No.19 is a setting for Bank-0 of LOCAL-Z to read data from character-ROM.
・No.20 and No.21 are instructions to read data from character-ROM. When CPU outputs 800000H address, this MMU
will convert and output 000000H address to external address bus:A23 to A0. And /CSZA for NOR-Flash will be
asserted because of logical address is in an area for CS2 at the same time.
By these instructions, CPU can read data from character ROM.
・No.23 is an instruction which changes Program bank number in the LOCAL-area. This setting is disabled.
・No.24 and No.25 are instructions to write data to SRAM. When CPU outputs 400000H address, this MMU will convert
and output 200000H address to external address bus:A23 to A0. And /CS1 for SRAM will be asserted because of
logical address is in an area for CS1 at the same time.
By these instructions, CPU can write data to SRAM.
・No.28 and No.29 are setting to set LCD starting address to LCD Controller. When LCDC outputs 400000H address in
DMA-cycle, this MMU will convert and output 200000H address to external address bus:A23 to A0. And /CS1 for
SRAM will be asserted because of logical address is in an area for CS1 at the same time.
By these instructions, LCDC can read data from SRAM.
・No.30 is an instruction to start LCD display operation.
No Instruction
16 org 400000H
17 ld (localwy),81H
18 ld (locally), 81H
19 ld (localrz), 80H
20 ld xiy,800000H
21 ld wa,(xiy)
22 :
23 ld (localpy), 82H
24 ld xix, 400000H
25 ld (xix), bc
26 :
27 :
28 ld xiz, 400000H
29 ld (lsarcl), xiz
30 ld (lcdctl0),01H
31 :
32 ret
92CH21-142
TMP92CH21
Comment
;
; Bank1 in LOCAL-Y is set as Write data for
LCD Display RAM
; Bank1 in LOCAL-Y is set as LCD display data
for LCD Display RAM
; Bank0 in LOCAL-Z is set as Read data
for Character-ROM
; Index address register to read
Character-ROM
; Reading Character-ROM
; Convert it to display-data
;
; Index address register to write LCD
Display data
; Writing LCD Display data
; Setting LCD Controller
;
; Setting LCD Start address to LCDC
;
; Start LCD Display operation
;
;