D950-CORE datasheet(23/89 Pages) STMICROELECTRONICS

Il numero della parte	D950-CORE

Spiegazioni elettronici	16-Bit Fixed Point Digital Signal Processor DSP Core

PDF	89 Pages

Scroll/Zoom	100%

Produttore elettronici	STMICROELECTRONICS [STMicroelectronics]

Homepage	http://www.st.com

Logo

23 / 89 page

23/89

D950-Core

3: Bit reverse addressing (on X-memory space only) with post-increment

This mode can be selected for AX0, AX1 (see RX0, RX1 bits of STA register).

It generates the bit-reversed address for 2k point FFT implementation (Index

value = 2k-1).

4: Indirect indexed addressing. The address of the operand is the sum of the con-

tents of the address register (AXi, AYi, SPX or SPY) and the contents of the se-

lected index register (IXi or IYi). This addition occurs before the operand is ac-

cessed and therefore requires an extra instruction cycle. The contents of the se-

lected address and index registers are unchanged.

Figures 4.8 and 4.9 show the schematics for indirect addressing with and without post

modification.

Figure 4.8

Indirect Addressing with Post-Modification

Figure 4.9

Indirect Indexed Addressing without Post-Modification

value

address

Memory

- linear

- bit-reverse

- modulo

index reg.

address reg.

VR02017H