MC68HC908GR16 Datasheet, PDF (143/310 Pages) Motorola, Inc – Microcontrollers

Freescale Semiconductor, Inc.
Input/Output Ports (PORTS)
Port E
READ DDRE ($000C)
WRITE DDRE ($000C)
RESET
WRITE PTE ($0008)
DDREx
PTEx
PTEx
READ PTE ($0008)
Figure 12-19. 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 12-6 summarizes the operation of the port E pins.
Table 12-6. Port E Pin Functions
DDRE PTE
Bit
Bit
0
X⁽¹⁾
1
X
I/O Pin
Mode
Input, Hi-Z⁽²⁾
Output
Accesses
to DDRE
Read/Write
DDRE5–DDRE0
DDRE5–DDRE0
1. X = Don’t care
2. Hi-Z = High impedance
3. Writing affects data register, but does not affect input.
Accesses
to PTE
Read
Write
Pin
PTE5–PTE0⁽³⁾
PTE5–PTE0
PTE5–PTE0
MC68HC908GR16 — Rev. 1.0
MOTOROLA
Input/Output Ports (PORTS)
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Data Sheet
143