UPD78F9502MA-CAC-A NEC, UPD78F9502MA-CAC-A Datasheet - Page 30

• Manufacturer Part Number: UPD78F9502MA-CAC-A
• Description: 8BIT MCU, 4K FLASH, 128B RAM, SMD
• Manufacturer: NEC

Specifications of UPD78F9502MA-CAC-A

• Controller Family/series: UPD78F
• No. Of I/o's: 8
• Ram Memory Size: 128Byte
• Cpu Speed: 10MHz
• No. Of Timers: 2
• No. Of Pwm: RoHS Compliant
• Core Size: 8bit
• Program Memory Size: 4KB
• Oscillator Type: External, Internal

3.2 Processor Registers
3.2.1 Control registers
control registers include a program counter, a program status word, and a stack pointer.
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The PD78F9500, 78F9501, 78F9502 provide the following on-chip processor registers.
The control registers have special functions to control the program sequence statuses and stack memory. The
(1) Program counter (PC)
(2) Program status word (PSW)
PC
The program counter is a 16-bit register which holds the address information of the next program to be
executed.
In normal operation, the PC is automatically incremented according to the number of bytes of the instruction to
be fetched. When a branch instruction is executed, immediate data or register contents are set.
Reset signal generation sets the reset vector table values at addresses 0000H and 0001H to the program
counter.
The program status word is an 8-bit register consisting of various flags to be set/reset by instruction execution.
Program status word contents are stored in stack area upon interrupt request generation or PUSH PSW
instruction execution and are restored upon execution of the RETI and POP PSW instructions.
Reset signal generation sets PSW to 02H.
PC15
15
PC14
PC13 PC12 PC11 PC10 PC9
PSW
Figure 3-8. Program Status Word Configuration
IE
7
Figure 3-7. Program Counter Configuration
Preliminary User’s Manual U18681EJ1V0UD
CHAPTER 3 CPU ARCHITECTURE
Z
0
PC8
AC
PC7
0
PC6
0
PC5
1
PC4
CY
PC3
0
PC2
PC1
PC0
0