UPD78F0537DGA(T)-9EV-A NEC, UPD78F0537DGA(T)-9EV-A Datasheet - Page 100

• Manufacturer Part Number: UPD78F0537DGA(T)-9EV-A
• Description: 8BIT MCU, 128K FLASH, 7KB RAM, SMD
• Manufacturer: NEC

Specifications of UPD78F0537DGA(T)-9EV-A

• Controller Family/series: UPD78
• No. Of I/o's: 55
• Ram Memory Size: 7KB
• Cpu Speed: 20MHz
• No. Of Timers: 8
• No. Of Pwm: RoHS Compliant
• Core Size: 8bit
• Program Memory Size: 128KB
• Oscillator Type: External, Internal

4.4.4 Instruction branch to bank area by interrupt
vector table, but it is difficult to identify the BANK register when the interrupt occurs.
7FFFH), specify the memory bank at the branch destination by using the BANK register in the common area, and
execute the CALL instruction. At this time, save the BANK register value before the change to RAM, and restore the
value of the BANK register before executing the RETI instruction.
100
When an interrupt occurs, instructions can branch to the memory bank specified by the BANK register by using the
Therefore, specify the branch destination address specified by the vector table in the common area (0000H to
Remark
• Software example (when using interrupt request of 16-bit timer/event counter 00)
VCTBL
RAMD
R_BNKRN: DS
BNKC
BNKITM000:
BN3
TEST:
END
CHAPTER 4 MEMORY BANK SELECT FUNCTION (
Allocate interrupt servicing that requires a quick response in the common area.
CSEG
DW
DSEG
CSEG
PUSH
MOV
MOV
MOV
CALL
MOV
MOV
POP
RETI
CSEG
MOV ⋅⋅⋅
RET
Common
area
Bank
area
:
:
AT
BNKITM000
SADDR
1
AT
AX
A,BANK
R_BNKRN,A
BANK,#BANKNUM TEST
!TEST
A,R_BNKRN
BANK,A
AX
BANK3
0020H
7000H
Memory bank m
Vector table
User’s Manual U17260EJ6V0UD
; Specifies an address at the timer interrupt destination.
; Saves the contents of the AX register.
; Restores the contents of the AX register.
; Secures RAM for saving the memory bank number before the interrupt occurs.
; Inter-memory bank interrupt servicing routine
; Saves the memory bank number before the interrupt to RAM.
; Specifies the memory bank number of the interrupt routine.
; Calls the interrupt routine.
; Restores the memory bank number before the interrupt.
; Interrupt servicing routine
Instruction branch
PD78F0536, 78F0537, AND 78F0537D ONLY)
Save the original memory bank number.
Specify the address and memory bank
at the destination, and execute the call
instruction.
Memory bank n