TMS320C67x DSP Architecture

1.4.1Central Processing Unit (CPU)

The C67x CPU, in Figure 1−1, is common to all the C62x/C64x/C67x devices. The CPU contains:

-Program fetch unit

-Instruction dispatch unit

-Instruction decode unit

-Two data paths, each with four functional units

-32 32-bit registers

-Control registers

-Control logic

-Test, emulation, and interrupt logic

The program fetch, instruction dispatch, and instruction decode units can deliver up to eight 32-bit instructions to the functional units every CPU clock cycle. The processing of instructions occurs in each of the two data paths (A and B), each of which contains four functional units (.L, .S, .M, and .D) and 16 32-bit general-purpose registers. The data paths are described in more detail in Chapter 2. A control register file provides the means to configure and control various processor operations. To understand how instructions are fetched, dispatched, decoded, and executed in the data path, see Chapter 4.

1.4.2Internal Memory

The C67x DSP has a 32-bit, byte-addressable address space. Internal (on-chip) memory is organized in separate data and program spaces. When off-chip memory is used, these spaces are unified on most devices to a single memory space via the external memory interface (EMIF).

The C67x DSP has two 32-bit internal ports to access internal data memory. The C67x DSP has a single internal port to access internal program memory, with an instruction-fetch width of 256 bits.

1.4.3Memory and Peripheral Options

A variety of memory and peripheral options are available for the C6000 platform:

-Large on-chip RAM, up to 7M bits

-Program cache

-2-level caches

-32-bit external memory interface supports SDRAM, SBSRAM, SRAM, and other asynchronous memories for a broad range of external memory requirements and maximum system performance.

1-8

Introduction

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Texas Instruments TMS320C67X/C67X+ DSP manual Central Processing Unit CPU, Internal Memory, Memory and Peripheral Options