Freescale Semiconductor MC68HC08KH12 manual Port C, Port B Pin Functions, 190

When bit DDRBx is a logic one, reading address $0001 reads the PTBx data latch. When bit DDRBx is a logic zero, reading address $0001 reads the voltage level on the pin. The data latch can always be written, regardless of the state of its data direction bit. Table 12-3summarizes the operation of the port B pins.

		Table 12-3. Port B Pin Functions
				Accesses to	Accesses to PTB
DDRB	PTB Bit		I/O Pin Mode	DDRB
Bit
				Read/Write	Read	Write
0	X(1)		Input, Hi-Z(2)	DDRB[7:0]	Pin	PTB[7:0](3)
1	X		Output	DDRB[7:0]	PTB[7:0]	PTB[7:0]

1.X = don’t care

2.Hi-Z = high impedance

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

12.5 Port C

Port C is a 5-bit general-purpose bidirectional I/O port with software configurable pullups and current drive options.

12.5.1 Port C Data Register (PTC)

The port C data register contains a data latch for each of the five port C pins.

Address:

Read:

Write:

Reset:

$0002
Bit 7	6	5	4	3	2	1	Bit 0
0	0	0	PTC4	PTC3	PTC2	PTC1	PTC0

Unaffected by reset

= Unimplemented

Figure 12-7. Port C Data Register (PTC)

Advance Information	MC68HC(7)08KH12 — Rev. 1.1
190	Freescale Semiconductor