Instruction Sets

More documents

Recommendations

Info

80 CHAPTER 2 <strong>Instruction</strong> <strong>Sets</strong>16 Mbytes(24 bit address)programspace8 Mwords(23 bit address)data space64 kwords(16 bit address)I/O space8 bitsFIGURE 2.18Address spaces in the TMS320C55x.16 bits16 bitsmain data page 0main data page 1memorymappedregistersmain data page 2main data page 127FIGURE 2.19The C55x memory map.■D offset is calculated by the assembler; its value depends on whether you areaccessing a data page value or a memory-mapped register.SP addressing is used to access stack values in the data memory. The addressis calculated asA SP SPH[22 :15]|(SP S offset ). (2.3)
2.3 TI C55x DSP 81■■S offset is an offset supplied by the programmer.Register-bit direct addressing accesses bits in registers.The argument @bitoffsetis an offset from the least-significant bit of the register. Only a fewinstructions (register test, set, clear, complement) support this mode.PDP addressing is used to access I/O pages.The 16-bit address is calculated asA PDP PDP[15 : 6]|PDP offset . (2.4)■ The PDP offset identifies the word within the I/O page. This addressing modeis specified with the port( ) qualifier.Indirect addresses may be any of four different types:■ AR indirect addressing uses an auxiliary register to point to data.This addressingmode is further subdivided into accesses into data, register bits, and I/O.To access a data page, the AR supplies the bottom 16 bits of the address andthe top 7 bits are supplied by the top bits of the XAR register. For registerbits, the AR supplies a bit number. (As with register-bit direct addressing, thisonly works on the register bit instructions.) When accessing the I/O space,the AR supplies a 16-bit I/O address. This mode may update the value of theAR register. Updates are specified by modifiers to the register identifier, suchas adding after the register name. Furthermore, the types of modificationsallowed depend upon the ARMS bit of status register ST2_55:0 for DSP mode,1 for control mode. A large number of such updates are possible: examplesinclude *ARn, which adds 1 to the register for a 16-bit operation and 2 tothe register for a 32-bit operation;*(ARn AR0) writes the value ofARn AR0into ARn.■■■Dual AR indirect addressing allows two simultaneous data accesses, either foran instruction that requires two accesses or for executing two instructions inparallel. Depending on the modifiers to the register ID,the register value maybe updated.CDP indirect addressing uses the CDP register to access coefficients thatmay be in data space, register bits, or I/O space. In the case of data spaceaccesses, the top 7 bits of the address come from CDPH and the bottom 16come from the CDP. For register bits, the CDP provides a bit number. ForI/O space accesses specified with port( ), the CDP gives a 16 bit I/O address.Depending on the modifiers to the register ID, the CDP register value may beupdated.Coefficient indirect addressing is similar to CDP indirect mode, but is usedprimarily for instructions that require three memory operands per cycle.Any of the indirect addressing modes may use circular addressing,which is handyfor many DSP operations. Circular addressing is specified with theARnLC bit in status
Page 2 and 3: 56 CHAPTER 2 Instruction SetsMemory
Page 4 and 5: 58 CHAPTER 2 Instruction Setschange
Page 6 and 7: 60 CHAPTER 2 Instruction Sets2.2.1
Page 9 and 10: 2.2 ARM Processor 63The basic form
Page 11 and 12: 2.2 ARM Processor 65CMPCMNTSTTEQCom
Page 13 and 14: 2.2 ARM Processor 67this step. Thus
Page 15 and 16: 2.2 ARM Processor 69mode fetches a
Page 17 and 18: 2.2 ARM Processor 71Example 2.4 ill
Page 19 and 20: 2.2 ARM Processor 73while (i < N) {
Page 21 and 22: 2.2 ARM Processor 75the figure show
Page 23 and 24: 2.3 TI C55x DSP 77The C55x has a nu
Page 25: 2.3 TI C55x DSP 79register mnemonic
Page 29 and 30: 2.3 TI C55x DSP 83This instruction
Page 31 and 32: 2.3 TI C55x DSP 85The C55x provides
Page 33 and 34: Questions 87Q2-3 Answer the followi
Page 35 and 36: Lab Exercises 89Q2-19 Where are C55

Instruction Sets

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?