s908ey8ad4cfjer Freescale Semiconductor, Inc, s908ey8ad4cfjer Datasheet - Page 124

• Manufacturer Part Number: s908ey8ad4cfjer
• Description: M68hc08 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

Input/Output (I/O) Ports (PORTS)
Figure 12-15
When bit DDREx is a 1, reading address $0008 reads the PTEx data latch. When bit DDREx is a 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.
124
X = don’t care
Hi-Z = high impedance
1. Writing affects data register, but does not affect input.
DDRE
shows the port E I/O logic.
Bit
0
1
READ DDRE ($000A)
WRITE DDRE ($000A)
WRITE PTE ($0008)
READ PTE($0008)
PTE
Bit
X
X
MC68HC908EY16 • MC68HC908EY8 Data Sheet, Rev. 10
Input, Hi-Z
I/O Pin
Output
Mode
Table 12-5. Port E Pin Functions
RESET
Figure 12-15. Port E I/O Circuit
Accesses to DDRE
Table 12-5
Read/Write
DDREx
DDRE[1:0]
DDRE[1:0]
PTEx
summarizes the operation of the port E pins.
PTE[1:0]
Read
Pin
Accesses to PTE
PTE[1:0]
PTE[1:0]
Freescale Semiconductor
Write
PTEx
(1)