Standard Interrupt Latency; Pts Interrupt Latency - Intel 8XC196NT User Manual

5.4.2.1

Standard Interrupt Latency

In 64-Kbyte mode, the worst-case delay for a standard interrupt is 56 state times (4 + 39 + 11 +
2) if the stack is in external memory. In 1-Mbyte mode, the worst-case delay increases to 61 state
times (4 + 39 + 15 + 3). This delay time does not include the time needed to execute the first in-
struction in the interrupt service routine or to execute the instruction following a protected in-
struction. Figure 5-2 illustrates the worst-case scenario for both 64-Kbyte and 1-Mbyte modes.
1-Mbyte Mode 4 3 2 1
64-Kbyte Mode
4 3 2 1
Ending
Execution
Instruction
Interrupt
Interrupt
Set
Pending
Bit
1-Mbyte Mode 61 State Times
Response
Time
64-Kbyte Mode 56 State Times
5.4.2.2

PTS Interrupt Latency

In both 64-Kbyte and 1-Mbyte modes, the maximum delay for a PTS interrupt is 43 state times
(4 + 39) (Figure 5-3). This delay time does not include the added delay if a protected instruction
is being executed or if a PTS request is already in progress. See Table 5-4 for execution times for
PTS cycles.
39
39
End
"NORML"
"NORML"
Cleared
Figure 5-2. Standard Interrupt Response Time
STANDARD AND PTS INTERRUPTS
15 3
11 2
Call is If Stack
"PUSHA"
Forced External
12 6
12 6
If Stack
External
Interrupt Routine
A0261-02
5-9