MC908AS60ACFU Datasheet, PDF (260/414 Pages) Freescale Semiconductor, Inc – M68HC08 Microcontrollers

Input/Output Ports
Figure 22-16 shows the port E I/O logic.
READ DDRE ($000C)
WRITE DDRE ($000C)
RESET
WRITE PTE ($0008)
DDREx
PTEx
PTEx
READ PTE ($0008)
Figure 22-16. Port E I/O Circuit
When bit DDREx is a logic 1, reading address $0008 reads the PTEx data latch. When bit DDREx is a
logic 0, reading address $0008 reads the voltage level on the pin. The data latch can always be written,
regardless of the state of its data direction bit. Table 22-5 summarizes the operation of the port E pins.
Table 22-5. Port E Pin Functions
DDRE
PTE
Bit
Bit
I/O Pin
Mode
Accesses to DDRE
Read/Write
0
X
Input, Hi-Z
DDRE[7:0]
1
X
Output
DDRE[7:0]
X = don’t care
Hi-Z = high impedance
1. Writing affects data register, but does not affect input.
Accesses to PTE
Read
Write
Pin
PTE[7:0]⁽¹⁾
PTE[7:0]
PTE[7:0]
22.7 Port F
Port F is a 7-bit special function port that shares four of its pins with the timer interface module (TIMA-6)
and two of its pins with the timer interface module (TIMB) on the MC68HC908AZ60A. Note that PTF4,
PTF5 and PTF6 are only available on 64-pin package options.
MC68HC908AZ60A • MC68HC908AS60A • MC68HC908AS60E Data Sheet, Rev. 6
260
Freescale Semiconductor