SAFC161RI datasheet(25/60 Pages) SIEMENS

25 / 60 page

Semiconductor Group

1998-05-01

C161RI

Parallel Ports

The C161RI provides up to 76 IO lines which are organized into six input/output ports and one input

port. All port lines are bit-addressable, and all input/output lines are individually (bit-wise)

programmable as inputs or outputs via direction registers. The I/O ports are true bidirectional ports

which are switched to high impedance state when configured as inputs. The output drivers of three

IO ports can be configured (pin by pin) for push/pull operation or open-drain operation via control

registers. The other IO ports operate in push/pull mode, except for the I2C interface pins which are

open drain pins only. During the internal reset, all port pins are configured as inputs.

All port lines have programmable alternate input or output functions associated with them.

PORT0 and PORT1 may be used as address and data lines when accessing external memory,

while Port 4 outputs the additional segment address bits A22/19/17...A16 in systems where

segmentation is enabled to access more than 64 KBytes of memory.

Port 3 includes alternate functions of timers, serial interfaces, the optional bus control signal BHE

and the system clock output (CLKOUT).

Port 5 is used for the analog input channels to the A/D converter or timer control signals.

Port 6 provides the optional chip select signals and interface lines for the I2C module.

All port lines that are not used for these alternate functions may be used as general purpose IO

lines.

SAFC161RI Datasheet(PDF) 25 Page - Siemens Semiconductor Group