MC908JB16DWE Datasheet, PDF (278/332 Pages) Freescale Semiconductor, Inc – Microcontrollers

Input/Output (I/O) Ports
READ DDRE ($0009)
WRITE DDRE ($0009)
RESET
WRITE PTE ($0008)
READ PTE ($0008)
DDREx
PTEx
PTEx
Figure 14-13. 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 14-3 summarizes
the operation of the port E pins.
Table 14-5. Port E Pin Functions
DDRE
Bit
Accesses
PTE
Bit
I/O Pin Mode ^{to DDRE}
Read/Write
0
X⁽¹⁾
Input, Hi-Z^{(2) DDRE[4:0]}
1
X
Output
DDRE[4:0]
Notes:
1. X = don’t care.
2. Hi-Z = high impedance.
3. Writing affects data register, but does not affect input.
Accesses to PTE
Read
Pin
PTE[4:0]
Write
PTE[4:0]⁽³⁾
PTE[4:0]
14.7 Port Options
All pins of port A, port C, and port E have programmable pullup resistors.
Port D has programmable LED drive capability; PTD5–PTD2 each have
10mA high current sink, and PTD1–PTD0 each have 25mA high current
sink.
Technical Data
278
Input/Output (I/O) Ports
MC68HC908JB16 — Rev. 1.1
Freescale Semiconductor