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Function Return Values

Function return values are always passed using MCU registers. The following table lists the possible return types and the registers used for each.

Return Type Register Description
bit Carry Flag Single bit returned in the carry flag.
unsigned char,
1-byte pointer
R7 Single byte type returned in R7.
unsigned int,
2-byte ptr
R6 & R7 MSB in R6, LSB in R7.
unsigned long
R4-R7 MSB in R4, LSB in R7.
float R4-R7 32-Bit IEEE format.
generic pointer R1-R3 Memory type in R3, MSB R2, LSB R1.
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