19.5
Interrupt Response Time
The time from generation of an interrupt request until interrupt exception handling is performed
and fetching of the first instruction of the exception service routine is started (the interrupt
response time) is shown in table 19.9.
Table 19.9 Interrupt Response Time
Number of States
Peripheral
Item
NMI
RL
Modules
Notes
Time for priority decision and
1Icyc + 4Bcyc
1Icyc + 7Bcyc
1Icyc + 2Bcyc
SR mask bit comparison*
Wait time until end of
sequence being executed by
CPU
S – 1 (≥ 0) ×
Icyc
S – 1 (≥ 0) ×
Icyc
S – 1 (≥ 0) ×
Icyc
Time from interrupt exception 4 × Icyc
handling (save of SR and PC)
until fetch of first instruction of
exception handler is started
4 × Icyc
4 × Icyc
Response
time
Total
5Icyc + 4Bcyc
+ (S – 1)Icyc
5Icyc + 7Bcyc
+ (S – 1)Icyc
5Icyc + 2Bcyc
+ (S – 1)Icyc
Minimum
case
13Icyc
19Icyc
9Icyc
When Icyc:
Bcyc = 2:1
Maximum
case
36 + S Icyc
60 + S Icyc
20 + S Icyc
When Icyc:
Bcyc = 8:1
Icyc: One cycle of internal clock supplied to CPU, etc.
Bcyc: One CKIO cycle
S:
Latency of instruction
Note: * In the SH7750 and SH7750S including the case where the mask bit (IMASK) in SR is
changed, and a new interrupt is generated.
Rev. 6.0, 07/02, page 771 of 986
RENESAS [ RENESAS TECHNOLOGY CORP ]
