M38D59GCHP#U0 Renesas Electronics America, M38D59GCHP#U0 Datasheet - Page 124

• Manufacturer Part Number: M38D59GCHP#U0
• Description: IC 740/38D5 MCU QZ-ROM 80LQFP
• Manufacturer: Renesas Electronics America
• Series: 740/38000r

Specifications of M38D59GCHP#U0

• Core Processor: 740
• Core Size: 8-Bit
• Speed: 12.5MHz
• Connectivity: SIO, UART/USART
• Peripherals: LCD, LED, PWM, WDT
• Number Of I /o: 59
• Program Memory Size: 48KB (48K x 8)
• Program Memory Type: QzROM
• Ram Size: 2K x 8
• Voltage - Supply (vcc/vdd): 1.8 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -20°C ~ 85°C
• Package / Case: 80-LQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -

38D5 Group
Rev.3.04
REJ03B0158-0304
APPENDIX
Note on Programming
1. Processor Status Register
(1) Initialization of the processor status register
It is required to initialize the processor status register (PS) flags
which affect program execution. It is particularly essential to
initialize the T and D flags because of their effect on
calculations. Initialize these flags at the beginning of the
program.
<Reason>
At a reset, the contents of the processor status register (PS) are
undefined except for the I flag which is “1”.
Fig. 99 Initialization of processor status register flags
(2) How to refer the processor status register
To refer the contents of the processor status register (PS), execute
the PHP instruction once and then read the contents of (S+1). If
necessary, execute the PLP instruction to return the stored PS to
its original status.
Fig. 100 Stack memory contents after PHP instruction
execution
(S) + 1
May 20, 2008 Page 122 of 134
(S)
Initialize the flags
Main program
Reset
Stored PS
2. Decimal Calculations
(1) Instructions for decimal calculations
To perform decimal calculations, set the decimal mode (D) flag
to “1” with the SED instruction and execute the ADC or SBC
instruction. In that case, after the ADC or SBC instruction,
execute another instruction before the SEC, CLC, or CLD
instruction.
Fig. 101 Instructions for decimal calculations
(2) Status flag at decimal calculations
When the ADC or SBC instruction is executed in decimal mode
(D flag = “1”), three of the status flags (N, V, and Z) are disabled.
The carry (C) flag is set to “1” if a carry is generated and is
cleared to “0” if a borrow is generated as a result of a calculation,
so it can be used to determine whether the calculation has
generated a carry or borrow.
Initialize the C flag before each calculation.
Execute the SEC, CLC, or CLD instruction
Execute the ADC or SBC instruction
Set the decimal mode (D) flag to “1”
NOP