MC68HC908GT16CFB Freescale Semiconductor, MC68HC908GT16CFB Datasheet - Page 133

• Manufacturer Part Number: MC68HC908GT16CFB
• Description: IC MCU 16K FLASH 8MHZ SPI 44PQFP
• Manufacturer: Freescale Semiconductor
• Series: HC08r

Specifications of MC68HC908GT16CFB

• Core Processor: HC08
• Core Size: 8-Bit
• Speed: 8MHz
• Connectivity: SCI, SPI
• Peripherals: LVD, POR, PWM
• Number Of I /o: 36
• Program Memory Size: 16KB (16K x 8)
• Program Memory Type: FLASH
• Ram Size: 512 x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 8x8b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 44-QFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -

SS — Slave Select
12.5.2 Data Direction Register D
Data direction register D (DDRD) determines whether each port D pin is an input or an output. Writing a
1 to a DDRD bit enables the output buffer for the corresponding port D pin; a 0 disables the output buffer.
DDRD7–DDRD0 — Data Direction Register D Bits
Figure 12-15
Freescale Semiconductor
Data direction register D (DDRD) does not affect the data direction of port D pins that are being used
by the SPI module. However, the DDRD bits always determine whether reading port D returns the
states of the latches or the states of the pins. See
The PTD0/SS pin is the slave select input of the SPI module. When the SPE bit is clear, or when the
SPI master bit, SPMSTR, is set, the PTD0/SS pin is available for general-purpose I/O. When the SPI
is enabled, the DDRB0 bit in data direction register B (DDRB) has no effect on the PTD0/SS pin.
These read/write bits control port D data direction. Reset clears DDRD7–DDRD0, configuring all port D
pins as inputs.
1 = Corresponding port D pin configured as output
0 = Corresponding port D pin configured as input
shows the port D I/O logic.
Address:
Avoid glitches on port D pins by writing to the port D data register before
changing data direction register D bits from 0 to 1.
Reset:
Read:
Write:
MC68HC908GT16 • MC68HC908GT8 • MC68HC08GT16 Data Sheet, Rev. 5.0
READ DDRD ($0007)
WRITE DDRD ($0007)
WRITE PTD ($0003)
READ PTD ($0003)
DDRD7
$0007
Bit 7
0
Figure 12-14. Data Direction Register D (DDRD)
DDRD6
6
0
RESET
Figure 12-15. Port D I/O Circuit
DDRD5
5
0
NOTE
DDRD4
DDRDx
PTDx
4
0
Table
DDRD3
12-5.
3
0
DDRD2
2
0
PTDPUEx
DDRD1
1
0
V
DD
30 k
DDRD0
Bit 0
PTDx
0
Port D
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