MC9S12E128CPV Freescale Semiconductor, MC9S12E128CPV Datasheet - Page 522

• Manufacturer Part Number: MC9S12E128CPV
• Description: Microcontrollers (MCU) 16 Bit 16MHz
• Manufacturer: Freescale Semiconductor

Specifications of MC9S12E128CPV

• Data Bus Width: 16 bit
• Program Memory Type: Flash
• Program Memory Size: 128 KB
• Data Ram Size: 8 KB
• Interface Type: SCI, SPI
• Maximum Clock Frequency: 25 MHz
• Number Of Programmable I/os: 92
• Number Of Timers: 16 bit
• Operating Supply Voltage: 3.135 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Package / Case: LQFP-112
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 10 bit
• On-chip Dac: 8 bit, 2 Channel
• Lead Free Status / Rohs Status: No RoHS Version Available

Chapter 18 Multiplexed External Bus Interface (MEBIV3)
18.3.2.4
Read: Anytime when register is in the map
Write: Anytime when register is in the map
This register controls the data direction for port B. When port B is operating as a general-purpose I/O port,
DDRB determines the primary direction for each port B pin. A 1 causes the associated port pin to be an
output and a 0 causes the associated pin to be a high-impedance input. The value in a DDR bit also affects
the source of data for reads of the corresponding PORTB register. If the DDR bit is 0 (input) the buffered
pin input state is read. If the DDR bit is 1 (output) the associated port data register bit state is read.
This register is not in the on-chip memory map in expanded and special peripheral modes. Therefore, these
accesses will be echoed externally. It is reset to 0x00 so the DDR does not override the three-state control
signals.
522
Reset
DDRB
Field
7:0
W
R
Bit 7
Data Direction Port B
0 Configure the corresponding I/O pin as an input
1 Configure the corresponding I/O pin as an output
Data Direction Register B (DDRB)
0
7
6
0
6
Figure 18-5. Data Direction Register B (DDRB)
Table 18-4. DDRB Field Descriptions
MC9S12E128 Data Sheet, Rev. 1.07
5
0
5
4
0
4
Description
3
0
3
2
0
2
Freescale Semiconductor
1
0
1
Bit 0
0
0