SAF-C164SM Infineon Technologies, SAF-C164SM Datasheet - Page 112

• Manufacturer Part Number: SAF-C164SM
• Description: 16-Bit CMOS Microcontroller
• Manufacturer: Infineon Technologies

5.6
The PEC response time defines the time from the setting of an interrupt request flag of
an enabled interrupt source to the start of the PEC data transfer. The basic PEC
response time for the C164CM is 2 instruction cycles.
Figure 5-5
In
instruction N). The indicated source wins the prioritization round during cycle 2. In
cycle 3, a PEC transfer “instruction” is injected into the decode stage of the pipeline,
suspending instruction N+1 and clearing the source’s interrupt request flag to ‘0’. Cycle 4
completes the injected PEC transfer and resumes the execution of instruction N+1.
All instructions that entered the pipeline after setting of the interrupt request flag (N+1,
N+2) will be executed after the PEC data transfer.
Note: If instruction N reads any of the PEC control registers PECC7 … PECC0, when a
The minimum PEC response time is 3 states (6 TCL). This requires program execution
from the internal code memory, no external operand read requests, and setting the
interrupt request flag during the last state of an instruction cycle. When the interrupt
request flag is set during the first state of an instruction cycle, the minimum PEC
response time under these conditions is 4 state times (8 TCL).
The PEC response time is increased by all delays of the instructions in the pipeline that
are executed before starting the data transfer (including N).
User’s Manual
Figure 5-5
PEC request wins the current round of prioritization, this round is repeated and the
PEC data transfer is started one cycle later.
Pipeline Stage
FETCH
DECODE
EXECUTE
WRITEBACK
PEC Response Times
IR-Flag
Pipeline Diagram for PEC Response Time
above the respective interrupt request flag is set in cycle 1 (fetching of
1
0
Cycle 1
N - 1
N - 2
N - 3
N
PEC Response Time
Cycle 2
N + 1
N - 1
N - 2
5-22
N
Cycle 3
N + 2
N - 1
PEC
Interrupt and Trap Functions
N
C164CM/C164SM
Cycle 4
N + 2
N + 1
PEC
N
MCT04333
Derivatives
V1.0, 2002-02