MC908GZ60CFUE Datasheet, PDF (186/352 Pages) Freescale Semiconductor, Inc – Standard features, Features of the CPU08

Input/Output (I/O) Ports
READ DDRF ($0444)
WRITE DDRF ($0444)
RESET
WRITE PTF ($0440)
DDRFx
PTFx
PTFx
READ PTD ($0440)
Figure 13-22. Port F I/O Circuit
When bit DDRFx is a 1, reading address $0440 reads the PTFx data latch. When bit DDRFx is a 0,
reading address $0440 reads the voltage level on the pin. The data latch can always be written,
regardless of the state of its data direction bit. Table 13-7 summarizes the operation of the port F pins.
Table 13-7. Port F Pin Functions
DDRF PTF
Bit
Bit
I/O Pin
Mode
Accesses
to DDRF
Read/Write
0
X⁽¹⁾
Input, Hi-Z⁽²⁾
DDRF7–DDRF0
1
X
Output
DDRF7–DDRF0
1. X = Don’t care
2. Hi-Z = High impedance
3. Writing affects data register, but does not affect input.
Accesses
to PTF
Read
WritE
Pin
PTF7–PTF0⁽³⁾
PTF7–PTF0
PTF7–PTF0
13.9 Port G
Port G is an 8-bit special-function port that shares all eight of its pins with the analog-to-digital converter
(ADC) module.
13.9.1 Port G Data Register
The port G data register (PTG) contains a data latch for each of the eight port pins.
Address:
Read:
Write:
Reset:
Alternate Function:
$0441
Bit 7
6
5
4
3
2
PTG7
PTG6
PTG5
PTG4
PTG3
PTG2
AD23
AD22
AD21
Unaffected by reset
AD20
AD19
AD18
Figure 13-23. Port G Data Register (PTG)
1
PTG1
AD17
Bit 0
PTG0
AD16
MC68HC908GZ60 • MC68HC908GZ48 • MC68HC908GZ32 Data Sheet, Rev. 6
186
Freescale Semiconductor