sh66l16a SinoWealth Micro-Electronics Corp. Ltd, sh66l16a Datasheet - Page 7

• Manufacturer Part Number: sh66l16a
• Description: 16k 4-bit Low Power Micro-controller With Lcd Driver
• Manufacturer: SinoWealth Micro-Electronics Corp. Ltd

3. ROM
The ROM can address 16K X 16 bits of program area from $0000 to $3FFF.
3.1. Vector Address Area ($0000 to $0004)
The program is sequentially executed. There is an area address $0000 through $0004 that is reserved for a special interrupt
service routine such as starting vector address.
*JMP instruction can be replaced by any instruction.
3.2. Bank Switch Mapping
Program Counter (PC11 - PC0) can only address 4K ROM spaces. The bank switch technique is used to extend the CPU
address space. The lower 2K of the CPU address space maps to the lower 2K of ROM space (BANK0). The upper 2K of the
CPU addressing space maps to one of the seven banks (BANK 1, 2, 3, 4, 5, 6, 7) of the upper 14K of ROM. (According to the
Bank Register $1F)
The bank switch mapping is as follows:
Lower 2K
Upper 2K
Address
address
address
CPU
Address
$0000
$0001
$0002
$0003
$0004
ROM Space,
0000 - 07FF
0800-0FFF
(BANK 0)
(BANK 1)
$1F = 0
Instruction
ROM Space,
0000 - 07FF
1000 -17FF
(BANK 0)
(BANK 2)
JMP*
JMP*
JMP*
JMP*
JMP*
$1F = 1
ROM Space,
0000 - 07FF
1800 -1FFF
(BANK 0)
(BANK 3)
$1F = 2
Jump to Port interrupt service routine (PORTB & PORTC)
Jump to Base Timer interrupt service routine
Jump to External interrupt service routine
Jump to Timer0 interrupt service routine
ROM Space,
7
0000 - 07FF
2000 -27FF
(BANK 0)
(BANK 4)
Jump to RESET service routine
$1F = 3
Remarks
ROM Space,
0000 - 07FF
2800 -2FFF
(BANK 0)
(BANK 5)
$1F = 4
ROM Space,
0000 - 07FF
3000 -37FF
(BANK 0)
(BANK 6)
$1F = 5
SH66L16A
ROM Space,
0000 - 07FF
3800 -3FFF
(BANK 0)
(BANK 7)
$1F = 6