HD64F3672FXV Renesas Electronics America, HD64F3672FXV Datasheet - Page 65

• Manufacturer Part Number: HD64F3672FXV
• Description: IC H8/3672 MCU FLASH 48LQFP
• Manufacturer: Renesas Electronics America
• Series: H8® H8/300H Tinyr

Specifications of HD64F3672FXV

• Core Processor: H8/300H
• Core Size: 16-Bit
• Speed: 16MHz
• Connectivity: SCI
• Peripherals: PWM, WDT
• Number Of I /o: 26
• Program Memory Size: 16KB (16K x 8)
• Program Memory Type: FLASH
• Ram Size: 2K x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 5.5 V
• Data Converters: A/D 4x10b
• Oscillator Type: Internal
• Operating Temperature: -20°C ~ 75°C
• Package / Case: 48-LQFP
• For Use With: R0K436079S000BE - KIT DEV FOR H8/36079 W/COMPILER
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -

Bit Manipulation in a Register Containing a Write-Only Bit
Example 3: BCLR instruction executed designating port 5 control register PCR5
P57 and P56 are input pins, with a low-level signal input at P57 and a high-level signal input at
P56. P55 to P50 are output pins that output low-level signals. An example of setting the P50 pin as
an input pin by the BCLR instruction is shown below. It is assumed that a high-level signal will be
input to this input pin.
1. When the BCLR instruction is executed, first the CPU reads PCR5. Since PCR5 is a write-only
2. Next, the CPU clears bit 0 in the read data to 0, changing the data to H'FE.
3. Finally, H'FE is written to PCR5 and BCLR instruction execution ends.
Input/output
Pin state
PCR5
PDR5
Input/output
Pin state
PCR5
PDR5
BCLR
Prior to executing BCLR instruction
BCLR instruction executed
After executing BCLR instruction
Description on operation
register, the CPU reads a value of H'FF, even though the PCR5 value is actually H'3F.
As a result of this operation, bit 0 in PCR5 becomes 0, making P50 an input port. However,
bits 7 and 6 in PCR5 change to 1, so that P57 and P56 change from input pins to output pins.
To prevent this problem, store a copy of the PCR5 data in a work area in memory and
manipulate data of the bit in the work area, then write this data to PCR5.
#0,
P57
Input
Low
level
0
1
P57
Output
Low
level
1
1
@PCR5
P56
Input
High
level
0
0
P56
Output
High
level
1
0
P55
Output
Low
level
1
0
P55
Output
Low
level
1
0
The BCLR instruction is executed for PCR5.
P54
Output
Low
level
1
0
P54
Output
Low
level
1
0
P53
Output
Low
level
1
0
P53
Output
Low
level
1
0
Rev.4.00 Nov. 02, 2005 Page 39 of 304
P52
Output
Low
level
1
0
P52
Output
Low
level
1
0
P51
Output
1
0
P51
Output
Low
level
1
0
Low
level
REJ09B0143-0400
Section 2 CPU
P50
Input
High
level
0
0
P50
Output
Low
level
1
0