C517A_99 Datasheet, PDF (206/218 Pages) Siemens Semiconductor Group – 8-Bit CMOS Microcontroller

Power Saving Modes
C517A
9.7 State of Pins in Software Initiated Power Saving Modes
In the idle mode and in the software power down mode the port pins of the C517A have a well
defined status which is listed in the following table 9-1. This state of some pins also depends on the
location of the code memory (internal or external).
Table 9-1
Status of External Pins During Idle and Software Power Down Mode
Outputs
Last Instruction Executed from
Internal Code Memory
Idle
Power Down
ALE
High
Low
PSEN
High
Low
PORT 0
Data
Data
PORT 2
Data
Data
PORT 1, 3, 4, 5, 6 Data /
Data /
alternate outputs last output
P7.0
Data
Data
Last Instruction Executed from
External Code Memory
Idle
Power Down
High
Low
High
Low
Float
Float
Address
Data
Data /
Data /
alternate outputs last output
Data
Data
Semiconductor Group
9-8