C511_1 Datasheet, PDF (38/128 Pages) Siemens Semiconductor Group – 8-Bit CMOS Microcontroller

On-Chip Peripheral Units
Figure 6-15b
Driver Circuit of Port 1 pins P1.2 and P1.4 (when used for SLCK and STO)
Pin Control for SCLK
When the SSC is disabled, both Enable Push-pull and Tristate will be inactive, the pin behaves like
a standard IO pin.
In master mode and with SSC enabled, Enable Push-pull will be active and Tristate will be inactive.
In slave mode and with SSC enabled, Enable Push-pull will be inactive and Tristate will be active.
Pin Control for STO
When the SSC is disabled, both Enable Push-pull and Tristate will be inactive.
In master mode and SSC enabled, Enable Push-pull will be active and Tristate will be inactive.
In slave mode and SSC enabled, Enable Push-pull will be active.
If the transmitter is enabled (SLS and TEN active), Tristate will be inactive.
If the transmitter is disabled (either SLS or TEN inactive), Tristate will be active.
Semiconductor Group
6-5