UPD78F0886GA(A)-GAM-AX NEC, UPD78F0886GA(A)-GAM-AX Datasheet - Page 16

• Manufacturer Part Number: UPD78F0886GA(A)-GAM-AX
• Description: 8BIT MCU, 60K FLASH, 3KB RAM, CAN
• Manufacturer: NEC

Specifications of UPD78F0886GA(A)-GAM-AX

• Controller Family/series: UPD78F
• No. Of I/o's: 41
• Ram Memory Size: 3KB
• Cpu Speed: 20MHz
• No. Of Timers: 8
• No. Of Pwm Channels: 6
• Digital Ic Case Style: LQFP
• Core Size: 8bit
• Program Memory Size: 60KB
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

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2.1.3 Stack pointer (SP)
RAM area can be set as the stack area.
the stack memory.
SP
This is a 16-bit register that holds the start address of the memory stack area. Only the internal high-speed
The SP is decremented ahead of write (save) to the stack memory and is incremented after read (reset) from
Each stack operation saves/resets data as shown in Figures 2-4 and 2-5.
Caution Since RESET input makes SP contents undefined, be sure to initialize the SP before instruction
SP
SP + 1
SP + 2
SP _ 2
SP _ 2
SP _ 1
SP
SP
execution.
Lower half
register pairs
Upper half
register pairs
Lower half
register pairs
Upper half
register pairs
POP rp
instruction
PUSH rp
instruction
15
Figure 2-5. Data to Be Reset from Stack Memory
Figure 2-4. Data to Be Saved to Stack Memory
Figure 2-3. Stack Pointer Configuration
SP
SP
User's Manual U12326EJ4V0UM
SP + 1
SP + 2
CHAPTER 2 REGISTERS
SP _ 2
SP _ 2
SP _ 1
SP
SP
CALL, CALLF and
CALLT instructions
RET instruction
SP
PC15-PC8
PC7-PC0
PC15-PC8
PC7-PC0
SP
SP
SP + 1
SP + 2
SP + 3
SP _ 3
SP _ 3
SP _ 2
SP _ 1
SP
SP
0
RETI and RETB
instructions
Interrupt and
BRK instructions
PC15-PC8
PC7-PC0
PC15-PC8
PC7-PC0
PSW
PSW