MC68HC912B32MFU8 MOTOROLA [Motorola, Inc], MC68HC912B32MFU8 Datasheet - Page 17

Manufacturer Part Number

MC68HC912B32MFU8

Description

16-Bit Microcontroller

Manufacturer

MOTOROLA [Motorola, Inc]

Datasheet

1.MC68HC912B32MFU8.pdf (128 pages)

3.4.8 Port S

MC68HC912B32

MC68HC912B32TS/D

are set, the corresponding pin is configured for output. On reset the DDRT bits are cleared and the cor-

responding pin is configured for input.

When the PUPT bit in the TMSK2 register is set, all input pins are pulled up internally by an active pull-

up device. Pull-ups are disabled after reset.

Setting the RDPT bit in the TMSK2 register configures all port T outputs to have reduced drive levels.

Levels are at normal drive capability after reset. The TMSK2 register can be read or written anytime

after reset. Refer to 12 Standard Timer Module.

Port S is the 8-bit interface to the standard serial interface consisting of the serial communications in-

terface (SCI) and serial peripheral interface (SPI) subsystems. Port S pins are available for general-pur-

pose parallel I/O when standard serial functions are not enabled.

Port S pins serve several functions depending on the various internal control registers. If WOMS bit in

the SC0CR1 register is set, the P-channel drivers of the output buffers are disabled for bits 0 through 1

(2 through 3). If SWOM bit in the SP0CR1 register is set, the P-channel drivers of the output buffers are

disabled for bits 4 through 7. (wired-OR mode). The open drain control effects both the serial and the

general-purpose outputs. If the RDPSx bits in the PURDS register are set, the appropriate port S pin

drive capabilities are reduced. If PUPSx bits in the PURDS register are set, the appropriate pull-up de-

vice is connected to each port S pin which is programmed as a general-purpose input . If the pin is pro-

grammed as a general-purpose output, the pull-up is disconnected from the pin regardless of the state

of the individual PUPSx bits. See 13 Serial Interface.

MOTOROLA