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Chapter 22 DP512 Port Integration Module (S12XDP512PIMV2)

MC9S12XDP512 Data Sheet, Rev. 2.21

870

Freescale Semiconductor

22.3.2.56 Port J Data Direction Register (DDRJ)

Read: Anytime.

Write: Anytime.

This register configures each port J pin as either input or output.

The CAN forces the I/O state to be an output on PJ7 (TXCAN4) and an input on pin PJ6 (RXCAN4). The

IIC takes control of the I/O if enabled. In these cases the data direction bits will not change.

The SCI2 forces the I/O state to be an output for each port line associated with an enabled output (TXD2).

It also forces the I/O state to be an input for each port line associated with an enabled input (RXD2). In

these cases the data direction bits will not change.

The DDRJ bits revert to controlling the I/O direction of a pin when the associated peripheral module is

disabled.

76543210

DDRJ7

DDRJ6

DDRJ5

DDRJ4

DDRJ2

DDRJ1

DDRJ0

Reset

00000000

= Unimplemented or Reserved

Figure 22-58. Port J Data Direction Register (DDRJ)

Table 22-52. DDRJ Field Descriptions

Field

Description

7–0

DDRJ[7:4]

DDRJ[2:0]

Data Direction Port J

0 Associated pin is conﬁgured as input.

1 Associated pin is conﬁgured as output.

Note: Due to internal synchronization circuits, it can take up to 2 bus clock cycles until the correct value is read

on PTJ or PTIJ registers, when changing the DDRJ register.

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