MC68HC908GR16VFJ Freescale Semiconductor, MC68HC908GR16VFJ Datasheet - Page 127

• Manufacturer Part Number: MC68HC908GR16VFJ
• Description: IC MCU 16K FLASH 8MHZ SPI 32LQFP
• Manufacturer: Freescale Semiconductor
• Series: HC08r

Specifications of MC68HC908GR16VFJ

• Core Processor: HC08
• Core Size: 8-Bit
• Speed: 8MHz
• Connectivity: LIN, SCI, SPI
• Peripherals: LVD, POR, PWM
• Number Of I /o: 21
• Program Memory Size: 16KB (16K x 8)
• Program Memory Type: FLASH
• Ram Size: 1K x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 105°C
• Package / Case: 32-LQFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -

DDRB7–DDRB0 — Data Direction Register B Bits
Figure 12-8
When bit DDRBx is a 1, reading address $0001 reads the PTBx data latch. When bit DDRBx is a 0,
reading address $0001 reads the voltage level on the pin. The data latch can always be written,
regardless of the state of its data direction bit.
Freescale Semiconductor
1. X = Don’t care
2. Hi-Z = High impedance
3. Writing affects data register, but does not affect input.
These read/write bits control port B data direction. Reset clears DDRB7–DDRB0, configuring all port
B pins as inputs.
DDRB
Bit
0
1
1 = Corresponding port B pin configured as output
0 = Corresponding port B pin configured as input
shows the port B I/O logic.
PTB
X
Bit
Avoid glitches on port B pins by writing to the port B data register before
changing data direction register B bits from 0 to 1.
X
(1)
READ DDRB ($0005)
WRITE DDRB ($0005)
WRITE PTB ($0001)
READ PTB ($0001)
Input, Hi-Z
I/O Pin
Output
Mode
(2)
Table 12-3. Port B Pin Functions
RESET
MC68HC908GR16 Data Sheet, Rev. 5.0
Figure 12-8. Port B I/O Circuit
Accesses to DDRB
DDRB7–DDRB0
DDRB7–DDRB0
Table 12-3
Read/Write
NOTE
DDRBx
PTBx
summarizes the operation of the port B pins.
PTB7–PTB0
Read
Pin
Accesses to PTB
PTBx
PTB7–PTB0
PTB7–PTB0
Write
(3)
Port B
127