Section 19 Interrupt Controller (INTC)
SH7751 Group, SH7751R Group
Page 790 of 1128
R01UH0457EJ0301 Rev. 3.01
Sep 24, 2013
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 handler is started (the interrupt response time)
is shown in table 19.8.
Table 19.8 Interrupt Response Time
Number of States
Item
NMI
RL
Peripheral
Modules
Notes
Time for priority decision and
SR mask bit comparison
*
1Icyc + 4Bcyc
1Icyc + 7Bcyc
1Icyc + 2Bcyc
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
handling (save of SR and
PC) until fetch of first
instruction of exception
handler is started
4
×
Icyc
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
Legend:
Icyc:
One cycle of internal clock supplied to CPU, etc.
Bcyc: One CKIO cycle
S:
Latency of instruction
Note:
*
In the SH7751, this includes the case where the mask bit (IMASK) in SR is changed
and a new interrupt is generated.