Datasheet

12 - PARALLEL PORTS ST10F269

74/184

When the on-chip peripheral associated with

a Port 3 pin is configured to use both the alternate

input and output function, the descriptions above

apply to the respective current operating mode.

The direction must be set accordingly. Port 3 pins

with alternate input/output functions are: MTSR,

MRST, RxD0 and SCLK.

Note: Enabling the CLKOUT function automati-

cally enables the P3.15 output driver. Set-

ting bit DP3.15=’1’ is not required.

Figure 28 : Block Diagram of Port 3 Pin with Alternate Input or Alternate Output Function

Open Drain

Latch

Write ODP3.y

Read ODP3.y

Direction

Latch

Write DP3.y

Read DP3.y

Internal Bus

MUX

Alternate

Data

Input

Latch

Clock

P3.y

Output

Buffer

y = 13, 11...0

Port Output

Latch

Read P3.y

Write DP3.y

Alternate

Data Output

Port Data

Output