SH7721 datasheet(144/1524 Pages) RENESAS

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Section 3 DSP Operating Unit

Rev. 3.00 Jan. 18, 2008 Page 82 of 1458

REJ09B0033-0300

performs data transfers between the DSP unit registers and all virtual address spaces. For details,

refer to section 3.4, DSP Data Transfer Instructions.

(4)

DSP Unit Operation Instructions

DSP unit operation instructions are called DSP data operation instructions. These instructions are

provided to execute digital signal processing operations at high speed using the DSP. Instruction

codes for these instructions are 32 bits. The DSP data operation instruction fields consist of two

fields: field A and field B. In field A, a function for double data transfer instructions can be

described. In field B, ALU operation instructions and multiply instructions can be described. The

instructions described in fields A and B can be executed in parallel. A maximum of four

instructions (ALU operation, multiply, and two data transfers) can be executed in parallel. For

details, refer to section 3.5, DSP Data Operation Instructions.

Notes: 1. 32-bit instruction codes are handled as two consecutive 16-bit instruction codes.

Accordingly, 32-bit instruction codes can be assigned to a word boundary. 32-bit

instruction codes must be stored in memory, upper word and lower word, in this order,

in word units.

2. In little endian, the upper and lower words must be stored in memory as data to be

accessed in word units.

CPU core instruction

0000

1110

111100

111101

111110

A Field

B Field

12 11

26 25

Double-data transfer instruction

Single-data transfer instruction

DSP data operation instruction

Figure 3.1 DSP Instruction Format

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