04 IN

IN

• The IN (Load from I/O Space) instruction is used to load the value from an I/O register (A) into a General Purpose Register (Rd).

Instruction Syntax

IN Rd, A

• Rd: The destination register where the value from the I/O register A will be stored.
  • Can be any of the 32 general-purpose registers: R0–R31.
• A: The I/O register address or name where the value is located.
  • Must be within the range:
    • Hexadecimal: $00 - $3F
    • (Values outside this range will result in an error.)

Examples

Valid Instruction:

IN R19, 0x10

• R19: R19 is valid since it is within the register range R0–R31.
• A: 0x10 is within the valid I/O address range $00–$3F.
• Effect: Load the value from I/O address 0x10 into R19.

Valid Instruction:

IN R19, PIND

• R19: R19 is valid since it is within the register range R0–R31.
• A: PIND is the I/O address name corresponding to the I/O address 0x10, which is within the valid range $00–$3F.
• Effect: Load the value from I/O register PIND (I/O address 0x10) into R19.