TMS320C25 DSP Architecture and Features

1. TMS320C25 DSP Architecture and Features Ehsan Shams Saeed Sharifi Tehrani

2. What is DSP ? Digital Signal Processing (DSP) is used in a wide variety of applications, and it is hard to find a good definition that is general. • changing or analyzing information which is measured as discrete sequences of numbers TMS320C25 DSP

3. DSP Algorithm Example : Digital Filters (e.g. Digital FIR Filters ,...) • Most share common features: • They use a lot of maths (multiplying and adding signals) • They deal with signals that come from the real world • They require a response in a certain time TMS320C25 DSP

4. Why DSP Processors? A Comparison : • As shown ,DSP Processors are more efficient TMS320C25 DSP

5. Why DSP Processors? (Contd.) As in FIR Filters TMS320C25 DSP

6. Texas Instruments,the company designer and supplier of digital signal processing and analog technologies Six decades of history TI envisions a world where every wireless call, every phone call and every Internet connection is touched by a Digital Signal Processor (DSP). TMS320C25 DSP

7. History of the TMS320 family TMS320C1x,TMS320C2x, TMS320C3x, TMS320C4x, and TMS320C5x This family currently includes five generations of DSPs. TMS320C25, a CMOS 40-MHz digital signal processor capable of twice the performance of the TMS320C1x devices is capable of executing 10 million instructions per second. 24 additional instructions (133 total) eight auxiliary registers an eight-level hardware stack 4K words of on-chip program ROM low power dissipation inherent to CMOS TMS320C25 DSP

8. Architectural overview Harvard architecture On-chip memory ALU Multiplier Memory interface Serial ports Multiprocessing applications Direct Memory Access TMS320C25 DSP

9. TMS320C25 Functional Block Diagram TMS320C25 DSP

10. Memory Organization Total of 544 16-bit words of on-chip data RAM, Program and Data Memory 288 words are always data memory and the remaining 256 words may be configured as either program or data memory. The TMS320C2x can address a total of 64K words of data memory. TMS320C25 DSP

11. Memory Organization (Cntd.) spaces are distinguished externally by means of the PS, DS, and IS The on-chip program ROM can be mapped into the lower 4K words of program memory. This ROM is enabled when MP/MC is set to a logic low. Three separate address spaces for program memory, data memory, and I/O TMS320C25 DSP

12. Memory Organization (Auxiliary Registers) register file containing eight auxiliary registers (AR0–AR7). ARAU is useful for address manipulation it may also serve as an additional general-purpose arithmetic unit TMS320C25 DSP

13. Memory Organization (Memory Addressing Modes) In the direct addressing mode, the 9-bit data memory page pointer (DP) points to one of 512 pages, each page consisting of 128 words. When an immediate operand is used, it is contained either within the instruction word itself or in the word following the instruction opcode . In the indirect addressing mode, the currently selected 16-bit auxiliary register AR(ARP) addresses the data memory through the auxiliary register file bus(AFB). TMS320C25 DSP

14. CALU A typical ALU instruction: Scaling Shifter 1) Data is fetched from the RAM on the data bus, 2) Data is passed through the scaling shifter and the ALU ALU and accumulator 3) The result is moved into the accumulator. Multiplier;T and P registers TMS320C25 DSP

15. System Control 16-bit program counter (PC) hardware stack of eight locations TMS320C25 DSP

16. System Control (pipeline operations) the prefetch counter (PFC) the 16-bit microcall stack (MCS) register, the instruction register (IR), the queue instruction register (QIR). Two status registers, ST0 and ST1, contain the status of various conditions and modes. TMS320C25 DSP

17. System Control (Timer Operation+Repeat Counter) The TMS320C2x provides a memory-mapped 16-bit timer (TIM) register and a 16-bit period (PRD) register. The on-chip timer is a down counter that is continuously clocked by CLKOUT1. The repeat counter (RPTC) is an 8-bit counter.It can be loaded with a number from 0 to 255 . RPTC is cleared by reset. TMS320C25 DSP

18. External Memory and IO Interface A 16-bit parallel data bus (D15–D0), A 16-bit address bus (A15–A0), Data, program, and I/O space select (DS, PS, and IS) signals, and Various system control signals. 1) Program Internal RAM/Data Internal (PI/DI) 2) Program Internal RAM/Data External (PI/DE) 3) Program External/Data Internal (PE/DI) 4) Program External/Data External (PE/DE) 5) Program Internal ROM/Data Internal (PR/DI) 6) Program Internal ROM/Data External (PR/DE) TMS320C25 DSP

19. Interrupts three external maskable user interrupts (INT2–INT0), Internal interrupts are generated by the serial port (RINT and XINT), by the timer (TINT), and by the software interrupt (TRAP) instruction. The TMS320C2x has a built-in mechanism for protecting multicycle instructions from interrupts. TMS320C25 DSP

20. Serial Ports If the serial port is not being used, the DXR and DRR registers can be used as general-purpose registers. A full-duplex on-chip serial port provides direct communication with serial devices such as codecs, serial A/D converters, and other serial systems. TMS320C25 DSP

21. Direct Memory Access The flexibility of the TMS320C2x allows configurations to satisfy a wide range of system requirements: In a multiprocessor environment, the SYNC input can be used to greatly ease interface between processors. A standalone system (single processor), A multiprocessor with devices in parallel, A host/slave multiprocessor with shared global data memory space A peripheral processor For multiprocessing applications, the TMS320C2xs allocates global data memory space and communicates with that space via the BR (bus request) and READY control signals. TMS320C25 DSP