UPD78F0890GK(A)-GAJ-AX NEC, UPD78F0890GK(A)-GAJ-AX Datasheet - Page 83

• Manufacturer Part Number: UPD78F0890GK(A)-GAJ-AX
• Description: 8BIT MCU, 128K FLASH, 7K RAM, LQFP
• Manufacturer: NEC

Specifications of UPD78F0890GK(A)-GAJ-AX

• Controller Family/series: UPD78F
• No. Of I/o's: 55
• Ram Memory Size: 7KB
• Cpu Speed: 20MHz
• No. Of Timers: 10
• No. Of Pwm: RoHS Compliant
• Core Size: 8bit
• Program Memory Size: 128KB
• Oscillator Type: External, Internal

4.4 Selecting Memory Bank
addressed. Therefore, to access a memory bank different from the one currently selected, that memory bank must be
selected by using the BANK register.
the memory bank, branch an instruction to the common area (0000H to 7FFFH) and change the value of the BANK
register in that area.
4.4.1 Referencing values between memory banks
change the setting of the BANK register there, and then reference a value.
The memory bank selected by the memory bank select register (BANK) is reflected on the bank area and can be
The value of the BANK register must not be changed in the bank area (8000H to BFFFH). Therefore, to change
Values cannot be directly referenced from one memory bank to another.
To access another memory bank from one memory bank, branch once to the common area (0000H to 7FFFH),
Cautions 1. Instructions cannot be fetched between different memory banks.
2. Branching and accessing cannot be directly executed between different memory banks.
3. Allocate interrupt servicing in the common area.
4. An instruction that extends from 7FFFH to 8000H can only be executed in memory bank 0.
Common
area
Common
area
Bank
area
Bank
area
CHAPTER 4 MEMORY BANK SELECT FUNCTION (
Execute branching or accessing between different memory banks via the common area.
Memory bank m
Memory bank m
User’s Manual U17554EJ4V0UD
Referencing value
Referencing value
PD78F0889, 78F0890 ONLY)
Memory bank n
Memory bank n
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