Texas Instruments MSP50C6xx Class 5 Instructions Memory Reference, Class 5 Instruction Encoding

Instruction Classification

4.4.5Class 5 Instructions: Memory Reference

Class 5 instructions provide transfer to and from data memory and all registers except accumulators and Rx which are included in classes 1 and 4. The registers referenced for both read and write operations are the multiplier register (MR), the product high register (PH), the shift value register (SV), the status register (STAT), the top of stack (TOS), the string register (STR), and the four accumulator pointer registers AP0 to AP3. The data pointer register (DP) is read only since its value is established by lookup table instructions. The RPT n (repeat) instruction is write only since repeated instructions cannot be interrupted. IRET and RET instructions are read only operations for popping the stack and are included in this class because the stack is memory mapped. Also included in this class are four flag instructions that modify flag memory and two instructions that multiply memory by MR, storing the results in the PH register.

Table 4–26. Class 5 Instruction Encoding

Bit	16	15	14	13	12	11	10	9	8	7	6	5	4	3	2	1	0
Class 5	1	1	0	1			C5						adrs
RET	1	1	0	1	1	1	1	0	0	0	1	1	1	1	1	1	0
IRET	1	1	0	1	1	1	1	0	1	0	1	1	1	1	1	1	0

Table 4–27. Class 5 Instruction Description

		C5			Mnemonic	Description
0	0	0	0	0	MOV {adrs}, SV	Store SV in the data memory location referred by addressing mode
						{adrs}, zero filled on upper 12 bits. Transfer status is modified.
0	0	0	0	1	MOV {adrs}, PH	Store the PH in the data memory location referred by addressing mode
						{adrs}. Transfer status is modified.
0	0	0	1	0	MOV {adrs}, STAT	Store the status (STAT) register contents to the data memory location
						referred by addressing mode {adrs} (17 bits including TAG). No
						modification of status.
0	0	0	1	1	MOV {adrs}, STR	Store string (STR) register contents to data memory location referred by
						addressing mode {adrs}, zero filled on upper 8 bits. Transfer status is
						modified.
0	0	1		n	MOV {adrs}, APn	Store the accumulator pointer (APn) register to the data memory location
						in {adrs}. The upper 10 bits are zero filled. Transfer status is modified.
0	1	0	0	0	MOV {adrs}, MR	Store the contents of the multiplier (MR) register in {adrs}. Transfer
						status is modified.
0	1	0	0	1	Reserved
0	1	0	1	0	MOV {adrs}, DP	Store the data pointer (DP) register contents to the location referred by
						{adrs}. Transfer status is modified.

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