HD6432621 Hitachi, HD6432621 Datasheet - Page 403

• Manufacturer Part Number: HD6432621
• Description: (HD64F262x Series) 16-Bit Microcomputer
• Manufacturer: Hitachi

Status Flag Clearing Timing: After a status flag is read as 1 by the CPU, it is cleared by writing
0 to it. When the DTC is activated, the flag is cleared automatically. Figure 10-46 shows the
timing for status flag clearing by the CPU, and figure 10-47 shows the timing for status flag
clearing by the DTC.
ø
Address
Status flag
Interrupt
request
signal
ø
Address
Write signal
Status flag
Interrupt
request
signal
Figure 10-47 Timing for Status Flag Clearing by DTC Activation
Figure 10-46 Timing for Status Flag Clearing by CPU
TSR write cycle
Source address
T1
TSR address
T1
read cycle
DTC
T2
T2
T1
write cycle
Destination
address
DTC
T2
359