Texas Instruments MSP50C6xx manual Bit, Byte, Word and String Addressing, C9c Mnemonic Description

Bit, Byte, Word and String Addressing

Table 4–38. Class 9c Instruction Description

C9c	Mnemonic	Description
0	MOV APn, imm6	Load the accumulator pointer (AP) with a 5-bit constant.
1	ADD APn, imm5	Add a 5-bit constant imm5 to the referenced accumulator pointer(AP).

Table 4–39. Class 9d Instruction Description

	C9d			Mnemonic	Description
0	0	0	0	BEGLOOP	Marks the beginning of loop. Queue interrupts and pushes the next PC value onto a
					temporary stack location.
0	0	0	1	ENDLOOP n	If R4 is not negative, pops the temporary stack value back on the PC and decrements
					R4 by n. If R4 is negative, the instruction is a NOP and execution will exit the loop. n is
					either 1 or 2
0	0	1	0	IDLE	Stops processor clocks. Device enters low power mode waiting on an interrupt to
					restart the clocks and execution.
1	0	0	0	INTE	Sets IM bit in status register to a 1, thus enabling interrupts.
1	0	0	1	INTD	Sets IM bit in status register to a 0, thus disabling interrupts.
1	0	1	0	SXM	Sets XM in status register to 1 enabling sign extension mode.
1	0	1	1	RXM	Sets XM in status register to 0, disabling sign extension mode.
1	1	0	0	SFM	Sets FM in status register to 1, enabling multiplier shift mode for signed fractional
					arithmetic.
1	1	0	1	RFM	Sets FM in status register to 0, enabling multiplier shift mode for unsigned fractional
					or integer arithmetic.
1	1	1	0	SOVM	Set OM bit in status register to 1, enabling ALU saturation output (DSP mode).
1	1	1	1	ROVM	Set OM bit in status register to 0, disabling the saturating ALU operation (normal
					mode).

4.5 Bit, Byte, Word and String Addressing

The MSP50P614/MSP50C614 has instructions which address bits, bytes, words and strings in data memory or program memory. Data memory is always accessed in bytes by the hardware, but is based on the instruction. The data memory location is treated as a byte, word, or flag address. There are five different kinds of addresses: byte addresses, byte-string addresses, word addresses, word-string addresses, and flag addresses. Each type of address is described below. Refer to Figure 4–3 and Table 4–40 for reference.

Byte and byte string address: Byte addressing is used to access individual bytes with an instruction in byte mode. Such instructions have a suffix, B, at the end of instruction name (for example, ADDB, MOVB, etc.). A byte string

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