HD64F2239TF20I Renesas Electronics America, HD64F2239TF20I Datasheet - Page 162

• Manufacturer Part Number: HD64F2239TF20I
• Description: MCU 3V 384K I-TEMP 100-TQFP
• Manufacturer: Renesas Electronics America
• Series: H8® H8S/2200r

Specifications of HD64F2239TF20I

• Core Processor: H8S/2000
• Core Size: 16-Bit
• Speed: 20MHz
• Connectivity: I²C, SCI, SmartCard
• Peripherals: DMA, POR, PWM, WDT
• Number Of I /o: 72
• Program Memory Size: 384KB (384K x 8)
• Program Memory Type: FLASH
• Ram Size: 32K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 3.6 V
• Data Converters: A/D 8x10b; D/A 2x8b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 100-TQFP, 100-VQFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -

Section 2 CPU
The bit manipulation operation is performed on this value that was read. In this example, bit 4 will
be cleared for H'F8.
After the bit manipulation operation, this data will be written to P1DDR, and the BCLR
instruction completes.
Although the instruction was expected to write H'E0 back to P1DDR, it actually wrote H'E8, and
P13, which was expected to be an input pin, is changed to function as an output pin. While this
section described the case where P13 was read out as a 1, since the values read are undefined
when P17 to P10 are read, when this bit manipulation instruction completes, bits that were 0 may
be changed to 1, and bits that were 1 may be changed to 0. To avoid this sort of problem, see
section 2.9.4, Access Methods for Registers with Write-Only Bits for methods for modifying
registers that include write-only bits.
Also note that it is possible to use the BCLR instruction to clear to 0 flags in internal I/O registers.
In this case, if it is clear from the interrupt handler or other information that the corresponding flag
is set to 1, then there is no need to read the value of the corresponding flag in advance.
2.9.4
Undefined values will be read out if a data transfer instruction is executed for a register that
includes write-only bits, or if a bit manipulation instruction is executed for a register that includes
write-only bits. To avoid reading undefined values, use methods such as those shown below to
access registers that include write-only bits.
The basic method for writing to a register that includes write-only bits is to create a work area in
internal RAM or other memory area and first write the data to that area. Then, perform the desired
access operation for that memory and finally write that data to the register that includes write-only
bits.
Rev. 6.00 Mar. 18, 2010 Page 100 of 982
REJ09B0054-0600
I/O
P1DDR
After bit
manipulation
I/O
P1DDR
Write value
Access Methods for Registers with Write-Only Bits
Output
Output
P17
P17
1
1
1
1
Output
Output
P16
P16
1
1
1
1
Output
Output
P15
P15
1
1
1
1
Output
Input
P14
P14
1
0
0
0
Output
Input
P13
P13
0
1
1
1
Input
Input
P12
P12
0
0
0
0
Input
Input
P11
P11
0
0
0
0
Input
Input
P10
P10
0
0
0
0