MC68HC08LT8 Datasheet, PDF (105/156 Pages) Freescale Semiconductor, Inc – Microcontrollers

READ DDRE ($0008)
WRITE DDRE ($0008)
RESET
WRITE PTE ($0009)
DDREx
PTEx
Port E
PTEx
READ PTE ($0009)
Figure 9-17. Port E I/O Circuit
When DDREx is a logic 1, reading address $0009 reads the PTEx data latch. When DDREx is a logic 0,
reading address $0009 reads the voltage level on the pin. The data latch can always be written,
regardless of the state of its data direction bit.
Table 9-5 summarizes the operation of the port E pins.
Table 9-6. Port E Pin Functions
DDRE
Bit
PTE Bit
I/O Pin Mode
Accesses to DDRE
Read/Write
0
X⁽¹⁾
Input, Hi-Z⁽²⁾
DDRE[7:0]
1
X
Output
DDRE[7:0]
1. X = don’t care; except.
2. Hi-Z = high impedance.
3. Writing affects data register, but does not affect input.
Accesses to PTE
Read
Write
Pin
PTE[7:0]⁽³⁾
PTE[7:0]
PTE[7:0]
MC68HC08LT8 Data Sheet, Rev. 1
Freescale Semiconductor
105