MC68HC(7)08KH12Rev. 1.1 Advance Information
Freescale Semiconductor 195
12.7 Port E
Port E is a 5-bit special function port that shares four of its pins with the
keyboard interrupt module (KBI) and shares three of its pins with the
timer interface module (TIM). PTE3–PTE0 pins have built-in schmitt
triggered input and software configurable pull-up; In addition,
PTE3–PTE0 pins have built-in optical interface circuit which can be
enabled via the Port-E Optical Interface Enable Register.
12.7.1 Port E Data Register (PTE)
The port E data register contains a data latch for each of the five port E
pins.
Table 12-5. Port D Pin Functions
DDRD
Bit PTD Bit I/O Pin Mode
Accesses to
DDRD Accesses to PTD
Read/Write Read Write
0X
(1) Input, Hi-Z(2) DDRD[7:0] Pin PTD[7:0](3)
1 X Output DDRD[7:0] PTD[7:0] PTD[7:0]
1. X = don’t care
2. Hi-Z = high impedance
3. Writing affects data register, but does not affect input.
Address: $0008
Bit 7654321Bit 0
Read: 0 0 0
PTE4 PTE3 PTE2 PTE1 PTE0
Write:
Reset: Unaffected by reset
= Unimplemented
Alternate
Function: KBE3 KBE2 KBE1 KBE0
Alternate
Function: TCH1 TCH0 TCLK
Figure 12-13. Port E Data Register (PTE)