Texas Instruments TMS320 Scaling shifter, 16 ⋅ 16-bit parallel multiplier, Timer, Memory control

Page 7

TMS320 SECOND-GENERATION

DEVICES

SPRS010B Ð MAY 1987 Ð REVISED NOVEMBER 1990

scaling shifter

The TMS320C2x scaling shifter has 16-bit input connected to the data bus and a 32-bit output connected to the ALU. The scaling shifter produces a left shift of 0 to 16 bits on the input data, as programmed in the instruction. The LSBs of the output are filled with zeroes, and the MSBs may be either filled with zeroes or sign-extended, depending upon the status programmed into the SXM (sign-extension mode) bit of status register ST1.

16 ⋅ 16-bit parallel multiplier

The 16 ⋅ 16-bit hardware multiplier is capable of computing a signed or unsigned 32-bit product in a single machine cycle. The multiplier has the following two associated registers.

•

•

A 16-bit Temporary Register (TR) that holds one of the operands for the multiplier, and

A 32-bit Product Register (PR) that holds the product.

Incorporated into the instruction set are single-cycle multiply/accumulate instructions that allow both operands to be processed simultaneously. The data for these operations may reside anywhere in internal or external memory, and can be transferred to the multiplier each cycle via the program and data buses.

Four product shift modes are available at the Product Register (PR) output that are useful when performing multiply/accumulate operations, fractional arithmetic, or justifying fractional products.

timer

The TMS320C2x provides a memory-mapped 16-bit timer for control operations. The on-chip timer (TIM) register is a down counter that is continuously clocked by CLKOUT1 on the TMS320C25. The timer is clocked by CLKOUT1/4 on the TMS32020. A timer interrupt (TINT) is generated every time the timer decrements to zero. The timer is reloaded with the value contained in the period (PRD) register within the next cycle after it reaches zero so that interrupts may be programmed to occur at regular intervals of PRD + 1 cycles of CLKOUT 1 on the TMS320C25 or 4 ⋅ PRD ⋅ CLKOUT 1 cycles on the TMS32020.

memory control

The TMS320C2x provides a total of 544 16-bit words of on-chip data RAM, divided into three separate blocks (B0, B1, and B2). Of the 544 words, 288 words (blocks B1 and B2) are always data memory, and 256 words (block B0) are programmable as either data or program memory. A data memory size of 544 words allows the TMS320C2x to handle a data array of 512 words (256 words if on-chip RAM is used for program memory), while still leaving 32 locations for intermediate storage. When using block B0 as program memory, instructions can be downloaded from external program memory into on-chip RAM and then executed.

When using on-chip program RAM, ROM, EPROM, or high-speed external program memory, the TMS320C2x runs at full speed without wait states. However, the READY line can be used to interface the TMS320C2x to slower, less-expensive external memory. Downloading programs from slow off-chip memory to on-chip program RAM speeds processing while cutting system costs.

The TMS320C2x provides three separate address spaces for program memory, data memory, and I/O. The on-chip memory is mapped into either the 64K-word data memory or program memory space, depending upon the memory configuration (see Figure 1). The CNFD (configure block B0 as data memory) and CNFP (configure block B0 as program memory) instructions allow dynamic configuration of the memory maps through software. Regardless of the configuration, the user may still execute from external program memory.

The TMS320C2x has six registers that are mapped into the data memory space: a serial port data receive register, serial port data transmit register, timer register, period register, interrupt mask register, and global memory allocation register.

POST OFFICE BOX 1443 • HOUSTON, TEXAS 77001

7

Page 6 Page 8
Image 7
Page 6 Page 8
Contents Description TMS320 SECOND-GENERATION Digital Signal ProcessorsPGA and PLCC/CER-QUAD PIN Assignments Signals DefinitionFunction PIN Introduction Wait States for Communication to Slower Off-Chip Key Features TMS32020Bit-Reversed Indexed-Addressing Mode for Memory SpaceType ArchitectureTMS320 Second-Generation Device Overview PackageSECOND-GENERATION Devices Functional block diagram TMS320C2xMemory control TimerScaling shifter 16 ⋅ 16-bit parallel multiplierMemory Maps TMS320 SECOND-GENERATION DevicesExternal interface Interrupts and subroutinesMultiprocessing Instruction set Repeat featureAddressing modes Symbol Definition Instruction SymbolsInstruction set summary TMS320C25 Instruction Set Summary ZAC SUBT²XOR XORK²LTP ² ApacLPH ² LTAData Memory Operations Mnemonic Description Words TMS320C25 Instruction Set Summary concluded TMS32020 Product Notification TMS32020Development support Software Tools Part Number TMS320 Second-Generation Software and Hardware SupportHardware Tools Part Number Documentation support Specification overviewMIN NOM MAX Unit Recommended operating conditionsParameter Test Conditions MIN TYP§ MAX Unit Internal clock option Clock Characteristics and TimingExternal clock option Test Load Circuit Parameter MIN TYP MAX Unit Memory and Peripheral Interface TimingHold Timing RS, INT, BIO, and XF TimingHold Holda Serial Port Timing MP/MC IOH INT Clkin / Clkx / ClkrTMS320C25GBA Parameter Test Conditions MIN TYP MAX Unit Clkin External Clock OptionVOH Min TdC1L-AL Low after CLKOUT1 low Serial Port Timing IPP1 Eprom ProgrammingSee Notes 14 VPPCLKIN, CLKX, Clkr INT0 INT2 VIHMP/MC VIL CLKOUT1, CLKOUT2 Internal Clock Option External clock optionFcrystal TdC1-S From Clkout if Is present TsuIN Setup before CLKOUT1 high MIN TYP MAX Contrast Summary of Electrical SpecificationsClock characteristics and timing ParameterSerial port timing Memory and peripheral interface timingRS, INT, BIO, and XF timing Hold timingClock timing Timing DiagramsBR, PS, D S Memory read timingReady CLKOUT1 CLKOUT2 Strb Memory write timingMSC One wait-state memory access timingIack Reset timingInterrupt timing TMS320C25 Interrupt timing TMS32020Serial port transmit timing Serial port receive timingExternal flag timing BIO timingPC = N PC = N + Execute Hold timing part aHold HoldaCLKOUT1 CLKOUT2 Hold timing part BHolda Fetch Fetch Execute Or is D15-D0 TdHH-AH TMS320C25FNL Plcc reflow soldering precautions Typical Supply Current Characteristics for TMS320C25Pin GB grid array ceramic package TMS32020, TMS320C25 Mechanical DataParameter MAX Unit Advance Jedec NO. Outline Terminals MIN MAX Fast programming and verification Programming the TMS320E25 Eprom cellEPT VPP Pin Nomenclature TMS320E25VCC EPTErasure TMS320E25 Programming Mode LevelsSignal Program Read Output Name ² PIN Verify Inhibit DisableProgram verify Fast Programming FlowchartRead Output disableROM protection and verification VSS Clkin EPT VPP TMS320E25 Protect and Verify Eprom Mode LevelsEprom protect VIH VIL PGM VPP VCCRbit EpromVCC VIH VIL PGM VIH/VOH HI-Z VIL/VOL VPP EPT VSS VIH VIL VPP VCCTMS320 SECOND-GENERATION NIL Other Qualified Versions of TMS320C25 Packaging InformationImportant Notice
Top Page Image Contents