PSD413A2 datasheet(55/123 Pages) STMICROELECTRONICS

55 / 123 page

PSD4XX Family

9.3.9.1 Control Register

This register is used in both Standard MCU I/O Mode and Address Out modes. For setting

a Standard MCU I/O Mode, a “1” must be written to the corresponding bit in the register.

Writing a “0” to the register is required for the Address Out mode. The register has a default

value of “0” after reset.

9.3.9.2 Direction Register

This register is used to control the direction of data flow in the I/O Ports. Writing a “1” to the

corresponding bit in the register configures the port to be an output port, and a “0” forces

the port to be an input port. The I/O configuration of the port pins can be determined by

reading the Direction Register. After reset, the pins are in input mode.

9.3.9.3 Open Drain

This register determines whether the output pin driver of Ports C or D is a CMOS driver or

an Open Drain driver. Writing a “0” to the register selects a CMOS driver, while a “1” selects

an Open Drain driver.

9.3.9.4 PLD – I/O Register

This is a read only status register. Reading a "1" indicates the corresponding pin is

configured as a PLD pin. A "0" indicates the pin is an I/O pin.

9.3.9.5 Data In Register

This register is used in the Standard MCU I/O Mode configuration to read the input pins.

9.3.9.6 Data Out Register

This register holds the output data in the Standard MCU I/O Mode. The contents of the

9.3.9.7 Macrocell Out Register

This register enables the user to read the outputs of the GPLD macrocell

(PA, PB, and PE macrocells).

9.3.9.8 I/O Register Address Offset

The I/O Register can be accessed by the microcontroller during normal read/write bus

cycles. The address of a register is defined as:

CSIOP + register address offset

The CSIOP is the base address that is defined in the ABEL file and occupies a 256 byte

space. The register address offset lies within this 256 byte space. Tables 16 and 16a are

the address offset of the registers.

The PSD4XX

Architecture

(cont.)

PSD413A2 Datasheet(PDF) 55 Page - STMicroelectronics