SH7721 datasheet(166/1524 Pages) RENESAS

166 / 1524 page

Section 3 DSP Operating Unit

Rev. 3.00 Jan. 18, 2008 Page 104 of 1458

REJ09B0033-0300

3.4.1

General Registers

The DSP instructions 10 general registers in the 16 general registers are used as address pointers

or index registers for double data transfers and single data transfers. In the following descriptions,

another register function in the DSP instructions is also indicated within parentheses [ ].

• Double data transfer instructions (X memory and Y memory are accessed simultaneously)

In double data transfers, X memory Y memory can be accessed simultaneously. To specify X

and Y memory addresses, two address pointers are supported.

Address Pointer

Index Register

X memory (MOVX.W)

R4,R5[Ax]

R8 [Ix]

Y memory (MOVY.W)

R6,R7[Ay]

R9 [Iy]

• Single data transfer instructions

In single data transfer, any virtual address space can be accessed via the L bus. The following

address pointers and index registers are used.

Address Pointer

Index Register

Any virtual space (MOVS.W/L)

R4,R5, R2, R3[As]

R8 [Is]

General registers (DSP mode)

X and Y double data transfers:

R4, 5

Single data transfers:

R4, 5, 2, 3

R6, 7

[Ax]

[Ix]

[As]

[Is]

[Ay]

[Iy]

: Address register set for the X data memory

: Index register for X address register set Ax

: Address register set for all data memories

: Index register used for single data transfers

: Address register set for the Y data memory

: Index register for Y address register set Ay

R10

R11

R12

R13

R14

R15

[As2]

[As3]

[As0]

[As1, Ax1]

[Ay0]

[Ay1]

[Ix, Is]

[Iy]

Figure 3.5 General Registers (DSP Mode)

SH7721 Datasheet(PDF) 166 Page - Renesas Technology Corp

SH7721 Datasheet(HTML) 166 Page - Renesas Technology Corp

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Datasheet Download

Link URL