UPD78F9222MC(T)-5A4-A NEC, UPD78F9222MC(T)-5A4-A Datasheet - Page 226

• Manufacturer Part Number: UPD78F9222MC(T)-5A4-A
• Description: 8BIT MCU, 4K FLASH, 256B RAM, 78F9222
• Manufacturer: NEC

Specifications of UPD78F9222MC(T)-5A4-A

• Controller Family/series: UPD78
• No. Of I/o's: 17
• Ram Memory Size: 256Byte
• Cpu Speed: 10MHz
• No. Of Timers: 4
• No. Of: RoHS Compliant
• Core Size: 8bit
• Program Memory Size: 4KB
• Oscillator Type: External, Internal

the interrupt is acknowledged after the instruction under execution is complete. Figure 12-8 shows an example of the
interrupt request acknowledgment timing for an 8-bit data transfer instruction MOV A, r. Since this instruction is
executed for 4 clocks, if an interrupt occurs for 3 clocks after the instruction fetch starts, the interrupt acknowledgment
processing is performed after the MOV A, r instruction is executed.
226
××IF:
××MK:
IE:
If an interrupt request flag (××IF) is set before an instruction clock n (n = 4 to 10) under execution becomes n − 1,
Interrupt
Clock
CPU
Interrupt request flag
Interrupt mask flag
Flag to control maskable interrupt request acknowledgment (1 = enable, 0 = disable)
Figure 12-8. Interrupt Request Acknowledgment Timing (Example of MOV A, r)
Figure 12-7. Interrupt Request Acknowledgment Processing Algorithm
No
MOV A, r
CHAPTER 12 INTERRUPT FUNCTIONS
Vectored interrupt
××MK = 0?
××IF = 1?
servicing
IE = 1?
Start
User’s Manual U16898EJ5V0UD
Yes (Interrupt request generated)
Yes
Yes
Saving PSW and PC, jump
No
No
to interrupt servicing
8 clocks
Interrupt request pending
Interrupt request pending
Interrupt servicing program