ST18952 datasheet(10/67 Pages) STMICROELECTRONICS

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ST18952

D950Core

The D950Core is a general purpose programmable 16-bit fixed point Digital Signal Processor

Core. The main blocks of the D950Core include an arithmetic data calculation unit, a program

control unit and an address calculation unit, able to manage up to 64k (program) and 128k

(data) x 16-bit memory spaces.

Memory

One 32 Kword and two 8 Kword single port memories are included on-chip:

• 32 Kword instruction memory on I space

• 8 Kword X-Data memory on X space

• 8 Kword Y-Data memory on Y space

One 512 word dual port memory is shared on X and Y spaces.

Memory can be extended off-chip for all three spaces in two ways:

1: Directly - Accesses to program and data memories can be performed simulta-

neously. Insertion of wait-states is necessary in case of nominal frequency

work.

2: Through the bus switch unit - Accesses to the different external spaces are mul-

tiplexed and wait-states are added.

Bus switch unit

The bus switch unit (BSU) is a bi-directional switcher which switches the 3 internal buses (I, X

and Y) to the external (E) bus.

DMA controller

The DMA controller manages data transfer between memories and external peripherals.

There are four independent DMA channels. Transfers can occur on X/Y/I spaces

(simultaneous transfers on X and Y spaces).

Interrupt controller

The interrupt controller (ITC) can manage up to eight external interrupts. Each source can be

individually activated and programmed as edge or level triggered. A ‘pending interrupt’ flag

displays the source waiting for service (this flag is writable to allow a software interrupt

capability). The priority of interrupts is programmable.

Timers

There are two timer (TIM) units on the ST18952. The timers enable interrupts to be generated

after predefined periods of time.

ST18952 数据表(PDF) 10 Page - STMicroelectronics