Freescale Semiconductor MC68HC908MR32 Port E Data Register, Port D Pin Functions, Pin PTD60

Input/Output (I/O) Ports (PORTS)

Figure 10-12shows the port D input logic.

INTERNAL DATA BUS

READ PTD ($0003)

PTDx

Figure 10-12. Port D Input Circuit

Reading address $0003 reads the voltage level on the pin. Table 10-4summarizes the operation of the port D pins.

Table 10-4. Port D Pin Functions

PTD Bit	Pin Mode	Accesses to PTD
		Read	Write
X(1)	Input, Hi-Z(2)	Pin	PTD[6:0](3)

1.X = don’t care

2.Hi-Z = high impedance

3.Writing affects data register, but does not affect input.

10.6 Port E

Port E is an 8-bit, special function port that shares five of its pins with the timer interface module (TIM) and two of its pins with the serial communications interface module (SCI).

10.6.1 Port E Data Register

The port E data register (PTE) contains a data latch for each of the eight port E pins.

Address:

Read:

Write:

Reset:

$0008
Bit 7	6	5	4	3	2	1	Bit 0
PTE7	PTE6	PTE5	PTE4	PTE3	PTE2	PTE1	PTE0

Unaffected by reset

Figure 10-13. Port E Data Register (PTE)

PTE[7:0] — Port E Data Bits

PTE[7:0] are read/write, software-programmable bits. Data direction of each port E pin is under the control of the corresponding bit in data direction register E.

NOTE

Data direction register E (DDRE) does not affect the data direction of port E pins that are being used by the TIMA or TIMB. However, the DDRE bits always determine whether reading port E returns the states of the latches or the states of the pins.

MC68HC908MR32 • MC68HC908MR16 Data Sheet, Rev. 6.1

108 Freescale Semiconductor