Intel 8XC251SB, 8XC251SA, 8XC251SP Ejmp @DRk Binary Mode Source Mode Bytes States Encoding, Eret

Models: Embedded Microcontroller 8XC251SP 8XC251SA 8XC251SQ 8XC251SB

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INSTRUCTION SET REFERENCE

EJMP @DRk

Binary Mode Source Mode

Bytes:

States:

[Encoding]

32

76

1 0 0 0

1 0 0 1

 

 

u u u u

Hex Code in:

Binary Mode = [A5] [Encoding]

 

Source Mode = [Encoding]

Operation:

EJMP

 

(PC) ((DRk))

 

 

ERET

 

Function:

Extended return

Description:

Pops byte 2, byte 1, and byte 0 of the 3-byte PC successively from the stack and

 

decrements the stack pointer by 3. Program execution continues at the resulting address,

 

which normally is the instruction immediately following ECALL.

Flags:

No flags are affected.

Example:

The stack pointer contains 0BH. On-chip RAM locations 08H, 09H and 0AH contain 01H,

 

23H and 49H, respectively. After executing the instruction

 

ERET

 

the stack pointer contains 08H and program execution continues at location 012349H.

 

Binary Mode Source Mode

Bytes:

States:

[Encoding]

32

109

1 0 1 0

1 0 1 0

 

 

Hex Code in: Binary Mode = [A5][Encoding]

Source Mode = [Encoding]

Operation: ERET (PC.23:16) ¨ ((SP)) (SP) ¨ (SP) – 1 (PC.15:8) ¨ ((SP)) (SP) ¨ (SP) – 1 (PC.7:0) ((SP)) (SP) (SP) – 1

INC <Byte>

Function: Increment

Description: Increments the specified byte variable by 1. An original value of FFH overflows to 00H. Three addressing modes are allowed for 8-bit operands: register, direct, or register-indirect.

Note: When this instruction is used to modify an output port, the value used as the original port data is read from the output data latch, not the input pins.

A-61

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Intel 8XC251SB, 8XC251SA manual Ejmp @DRk Binary Mode Source Mode Bytes States Encoding, Eret, INC Byte Function Increment