For using the DSP module in an optimum way, it is necessary to konw all DSP instructions. The list of DSP instructions, including the parameter description and application of the instruction is presented in table 11-2.

INSTRUCTION	INSTRUCTION AND PARAMETERS	PARAMETER DESCRIPTION	OPERATION DESCRIPTION
MAC	MAC Wm*Wn, Acc	Wm – W4 or W5 Wn – W6 or W7 Acc – A or B accumulator	Values of the Wm and Wn registers are multiplied and added to the current value in the operating accumulator (A or B)
MAC	MAC Wm*Wn, Acc, [Wx], Wxd, [Wy], Wyd	Wm – W4 or W5 Wn – W6 or W7 Acc – A or B accumulator Wx – W8 or W9 Wxd – W4 or W5 Wy – W10 or W11 Wyd – W6 or W7	Values of the Wm and Wn registers are multiplied and added to the current value in the operating accumulator (A or B), from the address pointed by the Wx register the value is read and written to the Wxd register, from the address pointed by the Wy register the value is read and written to the Wyd register.
MAC	MAC Wm*Wn, Acc, [Wx]+=kx, Wxd, [Wy]+=ky, Wyd	Wm – W4 or W5 Wn – W6 or W7 Acc – A or B accumulator Wx – W8 or W9 Wxd – W4 or W5 kx – (-6,-4,-2, 2, 4, 6) Wy – W10 or W11 Wyd – W6 or W7 ky – (-6,-4,-2, 2, 4, 6)	Values of the Wm and Wn registers are multiplied and added to the current value in the operating accumulator (A or B), from the address pointed by the Wx register the value is read and written to the Wxd register, from the address pointed by the Wy register the value is read and written to the Wyd register, the Wx register value is decreased by kx, the Wy register value is decreased by ky.
MOVSAC	MOVSAC Acc[Wx], Wxd, [Wy], Wyd, AWB	Acc – A or B accumulator Wx – W8 or W9 Wxd – W4 or W5 Wy – W10 or W11 Wyd – W6 or W7 AWB – W13 (Acc write-back)	The value from the operating accumulator is saved in the register W13 (AWB - accumulator write back), from the address pointed by the register Wx the value is read and written to the register Wxd, from the address pointed by the register Wy the value is read and written to the register Wyd.
MPY	MPY Wm*Wn, Acc	Wm – W4 or W5 Wn – W6 or W7 Acc – A or B accumulator	The values in the Wm and Wn registers are multiplied and written to the operating accumulator.
MPY	MPY Wm*Wn, Acc [Wx], Wxd, [Wy], Wyd	Wm – W4 or W5 Wn – W6 or W7 Acc – A or B accumulator Wx – W8 or W9 Wxd – W4 or W5 Wy – W10 or W11 Wyd – W6 or W7	The values of the Wm and Wn registers are muliplied and written to the accumulator (A or B), from the address pointed by the register Wx the value is read and written to the register Wxd, from the address pointed by the register Wy the value is read and written to the register Wyd.
MPY	MPY Wm*Wn, Acc [Wx]+=kx, Wxd, [Wy]+=ky, Wyd	Wm – W4 or W5 Wn – W6 or W7 Acc – A or B accumulator Wx – W8 or W9 Wxd – W4 or W5 kx – (-6,-4,-2, 2, 4, 6) Wy – W10 or W11 Wyd – W6 or W7 ky – (-6,-4,-2, 2, 4, 6)	The values of the Wm and Wn registers are multiplied and written to the operating accumulator (A or B), from the address pointed by the Wx register the value is read and written to the Wxd register, from the address pointed by the Wy register the value is read and written to the Wyd register, the Wx register value is increased by kx, the Wy register value is increased by ky.
MPY	MPY Wm*Wn, Acc[Wx]-=kx, Wxd, [Wy]-=ky, Wyd	Wm – W4 or W5 Wn – W6 or W7 Acc – A or B accumulator Wx – W8 or W9 Wxd – W4 or W5 kx – (-6,-4,-2, 2, 4, 6) Wy – W10 or W11 Wyd – W6 or W7 ky – (-6,-4,-2, 2, 4, 6)	The values of the Wm and Wn registers are multiplied and written to the operating accumulator (A or B), from the address pointed by the Wx register the value is read and written to the Wxd register, from the address pointed by the Wy register the value is read and written to the Wyd register, the Wx register value is decreased by kx, the Wy register value is decreased by ky.
MSC	MSC Wm*Wn, Acc[Wx], Wxd, [Wy], Wyd	Wm – W4 or W5 Wn – W6 or W7 Acc – A or B accumulator Wx – W8 or W9 Wxd – W4 or W5 Wy – W10 or W11 Wyd – W6 or W7	The values of the Wm and Wn registers are multiplied and subtracted from the curent value in the operating accumulator (A or B), from the address pointed by the Wx register the value is read and written to the Wxd register, from the address pointed by the Wy register the value is read and written to the Wyd register.
MSC	MSC Wm*Wn, Acc[Wx]+=kx, Wxd, [Wy]+=ky, Wyd	Wm – W4 or W5 Wn – W6 or W7 Acc – A or B accumulator Wx – W8 or W9 Wxd – W4 or W5 kx – (-6,-4,-2, 2, 4, 6) Wy – W10 or W11 Wyd – W6 or W7 ky – (-6,-4,-2, 2, 4, 6)	The values of the Wm and Wn registers are multiplied and subtracted from the current value in the operating accumulator (A or B), from the address pointed by the Wx register the value is read and written to the Wxd register, from the address pointed by the Wy register the value is read and written to the Wyd register, the Wx register value is increased by kx, the Wy register value is increased by ky.
MSC	MSC Wm*Wn, Acc[Wx]-=kx, Wxd, [Wy]-=ky, Wyd	Wm – W4 or W5 Wn – W6 or W7 Acc – A or B accumulator Wx – W8 or W9 Wxd – W4 or W5 kx – (-6,-4,-2, 2, 4, 6) Wy – W10 or W11 Wyd – W6 or W7 ky – (-6,-4,-2, 2, 4, 6)	The values of the Wm and Wn registers are multiplied and subtracted from the current value in the operating accumulator (A or B), from the address pointed by the Wx register the value is read and written to the Wxd register, from the address pointed by the Wy register the value is read and written to the Wyd register, the Wx register value is decreased by kx, the Wy register value is decreased by ky.
NEG	NEG Acc	Acc – A or B (operating accumulator)	Acc ← -Acc, the sign of the current value in the accumulator is changed, analogous to the multiplying of the value in the operating accumulator by –1.
REPEAT	REPEAT #lit14	#lit14 – 14-bit unsigned value (0...16383)	The instruction following REPEAT will be executed #lit14+1 times. Even though this is not a DSP instruction, it is very often used when using DSP instructions.
REPEAT	REPEAT Wn	Wn – W0...W15	The instruction following REPEAT will be executed Wn+1 times. Even though this is not a DSP instruction, it is very often used when using DSP instructions.
SAC	SAC Acc, {#Slit4,} Wd	Acc – A or B accumulator {#Slit4,} – optional 4-bit constant Wd – W0...W15	If the optional 4-bit constant is specified, the accumulator value is shifted to the right for the positive value of the constant or to the left if the constant is negative. Then, the obtained value is loaded to Wd.
SAC	SAC Acc, {Slit4,} [Wd]	Acc - A or B accumulator {#Slit4,} – optional 4-bit constant Wd – W0...W15	If the optional 4-bit constant is specified, the accumulator value is shifted to the right for the positive value of the constant or to the left if the constant is negative. Then, the obtained value is loaded to the address in the data memory pointed by the Wd register.
SAC	SAC Acc, {Slit4,} [Wd++]	Acc - A or B accumulator {#Slit4,} – optional 4-bit constant Wd – W0...W15	If the optional 4-bit constant is specified, the accumulator value is shifted to the right for the positive value of the constant or to the left if the constant is negative. Then, the obtained value is loaded to the address in the data memory pointed by the Wd register. After memory write, the value of the register Wd is incremented by 2.
SAC	SAC Acc, {Slit4,} [Wd -]	Acc - A or B accumulator {#Slit4,} – optional 4-bit constant Wd – W0...W15	If the optional 4-bit constant is specified, the accumulator value is shifted to the right for the positive value of the constant or to the left if the constant is negative. Then, the obtained value is loaded to the address in the data memory pointed by the Wd register. After memory write, the value of the register Wd is decremented by 2.
SAC	SAC Acc, {Slit4,} [++Wd]	Acc - A or B accumulator {#Slit4,} – optional 4-bit constant Wd – W0...W15	If the optional 4-bit constant is specified, the accumulator value is shifted to the right for the positive value of the constant or to the left if the constant is negative. Then, the value of the register Wd is incremented by 2 and the value obtained by shifting is saved in the address pointed by the Wd register.
SAC	SAC Acc, {Slit4}, [--Wd]	Acc - A or B accumulator {#Slit4,} – optional 4-bit constant Wd – W0...W15	If the optional 4-bit constant is specified, the accumulator value is shifted to the right for the positive value of the constant or to the left if the constant is negative. Then, the value of the register Wd is decremented by 2 and the value obtained by shifting is saved in the address pointed by the Wd register.
SAC.R	The same as for SAC	The same as for SAC	The same as for the SAC instruction except that the value from the accumulator is rounded by the conventional or convergent mode.
SFTAC	SFTAC Acc, #Slit6	#Slit6 – 6-bit constant	Shift the value in the accumulator by #Slit6 bits. If the constant is positive, shifting is to the right, otherwise to the left.
SFTAC	SFTAC Acc, Wd	Wd – W0...W15	Shift the value in the accumulator by Wd bits. If the register Wd is positive, shifting is to the right, otherwise to the left.
CLR	CLR Acc	Acc - A or B accumulator	The value in the operating accumulator is set to zero.
CLR	CLR Acc, [Wx], Wxd, [Wy], Wyd	Acc - A or B accumulator Wx – W8 or W9 Wxd – W4 or W5 Wy – W10 or W11 Wyd – W6 or W7	The value in the operating accumulator is set to zero. From the address in the data memory pointed by Wx the value is read and written to the register Wxd. From the address in the data memory pointed by Wy the value is read and written to the register Wyd.
CLR	CLR Acc, [Wx]+=kx, Wxd, [Wy]+=ky, Wyd	Acc – A or B accumulator Wx – W8 or W9 Wxd – W4 or W5 kx – (-6,-4,-2, 2, 4, 6) Wy – W10 or W11 Wyd – W6 or W7 ky – (-6,-4,-2, 2, 4, 6)	The value in the operating accumulator is set to zero. From the address in the data memory pointed by Wx the value is read and written to the register Wxd. From the address in the data memory pointed by Wy the value is read and written to the register Wyd. The Wx register value is increased by kx, the Wy register value is increased by ky.

Table 11-2 List of DSP instructions with description of operations and parameters. Table 11-2 shows that some instructions (such as MAC) could have more than one form. All versions of the instructions have not been descibed, but the emphasis was put on the most frequently used versions, in order to illustrate the way of thinking when using DSP instructions. The structures of individual registers of the DSP module are given in Tables 11-3 to 11-6. NOTE: Reading of bits which have not been alocated any functions gives '0'.

NAME	ADR	15	14	13	12	11	10	9	8
CORCON	0x0044	-	-	-	US	EDT	DL<2:0>

7	6	5	4	3	2	1	0	RESET STATE
SATA	SATB	SATDW	ACCSAT	IPL3	PSV	RND	IF	0x0020

Table 11-3 Description of the CORCON register

US – DSP multiply unsigned/signed control bit 
     (1 – unsigned multiplication, 0 – signed multiplication)
EDT – Early DO loop termination control bit. This bit will always read as’0’.
      1 – Terminate executing DO lop at the end of current loop iteration
      0 – No effect
DL<2:0> - DO loop nesting level status bit
   111 – 7 nested DO loops active
   110 – 6 nested DO loops active
   ...
   001 – 1 nested DO loop active
   000 – 0 DO loops active
SATA – AccA  saturation enable bit
       1 – Accumulator A saturation enabled
       0 – Accumulator A saturation disabled 
SATB – AccB  saturation enable bit
       1 – Accumulator B saturation enabled
       0 – Accumulator B saturation disabled
SATDW – Data space write from DSP engine saturation enable bit
       1 – Data space write saturation enabled
       0 – Data space write saturation disabled
ACCSAT – Accumlator saturation mode select bit
         1 – 9.31 saturation (super saturation)
         0 – 1.31 saturation (normal saturation)
IPL3 – CPU interrupt priority level status bit
       1 – CPU interrupt priority level is greater than 7
       0 – CPU interrupt priority level is 7 or less
PSV – Program space visibility in data space enable bit 
      (1 – PSV visible in data space, 0 – PSV  not visible in data space)
RND – Rounding mode select bit 
      (1- conventional rounding enabled, 0 – convergent rounding enabled)
IF – Integer or fractional multiplier mode select bit 
     (1 – integer mode enabled, 0 – fractional mode enabled (1.15 radix))

NAME	ADR	47	46	45	44	43	42	41	40	39	38	37	36	35	34	33	32	RESET STATE
ACCAU	0x0026	SE								ACCAU								0x0000

Table 11-4a Description of the ACCA register

NAME	ADR	31	30	29	28	27	26	25	24	23	22	21	20	19	18	17	16	RESET STATE
ACCAH	0x0024	ACCAH																0x0000

Table 11-4b Description of the ACCA register

NAME	ADR	15	14	13	12	11	10	9	8	7	6	5	4	3	2	1	0	RESET STATE
ACCAL	0x0022	ACCAL																0x0000

SE – Sign extention for AccA accumulator Table 11-4c Description of the ACCA register

NAME	ADR	47	46	45	44	43	42	41	40	39	38	37	36	35	34	33	32	RESET STATE
ACCBU	0x002C	SE								ACCBU								0x0000

Table 11-5a Description of the ACCB register

NAME	ADR	31	30	29	28	27	26	25	24	23	22	21	20	19	18	17	16	RESET STATE
ACCBH	0x002A	ACCBH																0x0000

Table 11-5b Description of the ACCB register

NAME	ADR	15	14	13	12	11	10	9	8	7	6	5	4	3	2	1	0	RESET STATE
ACCBL	0x0028	ACCBL																0x0000

SE – Sign extention for AccB accumulator Table 11-5c Description of the ACCB register

name	ADR	15	14	13	12	11	10	9	8	7	6	5	4	3	2	1	0	Reset State
SR	0x0042	OA	OB	SA	SB	OAB	SAB	DA	DC	IPL<2:0>			RA	N	OV	Z	C	0x0000

SE – Sign extention for AccB accumulator Table 11-6 Description of the SR register

OA – Accumulator A overflow status bit 
     (1 – accumulator A overflowed, 0 – accumulator A has not overflowed)
OB - Accumulator B overflow status bit 
     (1 – accumulator B overflowed, 0 – accumulator B has not overflowed)
SA – Accumulator A saturation ‘sticky’ status bit. 
     This bit can be cleared or read but not set to ‘1’.
     1 – accumulator A is saturated or has been saturated at some time
     0 – accumulator A is not saturated
SB – Accumulator B saturation ‘sticky’ status bit. 
     This bit can be cleared or read but not set to ‘1’.
     1 – accumulator B is saturated or has been saturated at some time
     0 – accumulator B is not saturated
OAB - OA¦¦OB combined accumulator overflow status bit
      1 – accumulators A or B have overflowed
      0 – neither accumulator A or B have overflowed
SAB - SA¦¦SB combined accumulator ‘sticky’ status bit
      1 – accumulators A or B saturated or have been saturated at some time
      0 – neither accumulator A or B are saturated
DA – DO loop active bit 
     (1 – DO loop in progress, 0 – DO loop not in progress)
DC – MCU ALU half carry/borrow bit (1 – a carry-out from the 4th order bit 
     (8-bit operations) or 8th order bit (16-bit operations) of the result occured, 
     0 – no carry-out from the 4th order bit (8-bit operations) or
     8th order bit (16-bit operations) of the result occured )
IPL<2:0> - CPU internal priority level status bit. 
           These bits are concatenated with the IPL<3> bit (CORCON<3>) to form 
           the CPU interrupt priority level.
    111 – CPU interrupt priority level is 7(15). User interrupts disabled.
    110 – CPU interrupt priority level is 6(14). User interrupts disabled.
    ...
    001 – CPU interrupt priority level is 1(9). User interrupts disabled.
    000 – CPU interrupt priority level is 0(8). User interrupts disabled.
    
RA – REPEAT loop active bit 
     (1 – REPEAT loop in progress, 0 – REPEAT loop not in progress)
N – MCU ALU negative bit 
    (1- result was negative, 0 – result was non-negative (zero or positive)
OV – MCU ALU overflow bit (1 – overflow occured for signed arithmetic, 
     0 – no ovwerflow occured). This bit is used for signed arithmetic (2’s complement).
     It indicates an overflow of the  magnitude which causes the sign bit to 
     change state.
Z – MCU ALU Zero bit (1 – a zero result, 0 – a non-zero result)
C – MCU ALU carry/borrow bit (1 – a carry-out from the MS bit of the result occured, 
    0 – no carry-out from the MS bit of the result occured)