Panasonic MN103001G/F01K

Extension Instruction Specifications

3-23

MCST (Multiply-and-accumulate operation results 8-, 16-, 32-bit saturation operation instruction)

[Instruction Format (Macro Name)]

MCST Dm, Dn

MCST imm8, Dn

[Assembler Mnemonic]

udf02 Dm, Dn

udf02 imm8, Dn : Only 0x20, 0x10, and 0x08 are valid as values for imm8

[Operation]

This instruction sets the contents of the multiply-and-accumulate operation overflow detect register MCVF in the V

flag. In addition, depending on the value of Dm or imm8, the following operations are performed.

(1) When the value of Dm or imm8 is 32 (0x00000020)

When the 64-bit result of the multiply-and-accumulate operation that is stored in the multiply-and-accumulate

registers MCRH and MCRL is equal to or greater than the maximum positive value for a 32-bit signed numeric

value (0x000000007fffffff), the maximum positive value (0x7fffffff) is stored in Dn. If the value stored in the

multiply-and-accumulate registers MCRH and MCRL is equal to or less than the maximum negative value for a 32-

bit signed numeric value (0xffffffff80000000), the maximum negative value (0x80000000) is stored in Dn. In all

other cases, the contents of MCRL are stored in Dn.

(2) When the value of Dm or imm8 is 16 (0x00000010)

When the 64-bit result of the multiply-and-accumulate operation that is stored in the multiply-and-accumulate

registers MCRH and MCRL is equal to or greater than the maximum positive value for a 16-bit signed numeric

value (0x0000000000007fff), the maximum positive value (0x00007fff) is stored in Dn. If the value stored in the

multiply-and-accumulate registers MCRH and MCRL is equal to or less than the maximum negative value for a 16-

bit signed numeric value (0xffffffffffff8000), the maximum negative value (0xffff8000) is stored in Dn. In all other

cases, the contents of MCRL are stored in Dn.

(3) When the value of Dm or imm8 is 8 (0x00000008)

When the 32-bit result of the multiply-and-accumulate operation that is stored in the multiply-and-accumulate

the maximum positive value (0x7f) is stored in Dn. If the value stored in the multiply-and-accumulate register

MCRL is equal to or less than the maximum negative value for an 8-bit signed numeric value (0xffffff80), the

maximum negative value (0x80) is stored in Dn. In all other cases, the contents of MCRL are stored in Dn.

(4) When the value of Dm or imm8 is any other value

The value in Dn is undefined.