TMS320VC5409 Fixed-Point Digital Signal ... - Texas Instruments

Documentation SupportTable 5−32. HPI8 Mode Switching Characteristics †‡§PARAMETER MIN MAX UNITten(DSL-HD) Enable time, HD driven from DS low 2 19 nstd(DSL-HDV1)Delay time, DS low to HDx valid forfirst byte of an HPI readCase 1a: Memory accesses whenDMAC is active in 16-bit mode andtw(DSH) < 18HCase 1b: Memory accesses whenDMAC is active in 16-bit mode andtw(DSH) ≥ 18HCase 1c: Memory access whenDMAC is active in 32-bit mode andtw(DSH) < 26HCase 1d: Memory access whenDMAC is active in 32-bit mode andtw(DSH) ≥ 26HCase 2a: Memory accesses whenDMAC is inactive and tw(DSH) < 10HCase 2b: Memory accesses whenDMAC is inactive and tw(DSH) ≥ 10H18H+19 – tw(DSH)1926H+19 – tw(DSH)1910H+19 – tw(DSH)Case 3: Register accesses 19td(DSL-HDV2) Delay time, DS low to HDx valid for second byte of an HPI read 19 nsth(DSH-HDV)R Hold time, HDx valid after DS high, for a HPI read 3 5 nstv(HYH-HDV) Valid time, HDx valid after HRDY high 5td(DSH-HYL) Delay time, DS high to HRDY low (see Note 1) 10 nstd(DSH-HYH)Delay time, DS high to HRDY highCase 1a: Memory accesses whenDMAC is active in 16-bit modeCase 1b: Memory accesses whenDMAC is active in 32-bit modeCase 2: Memory accesses whenDMAC is inactiveCase 3: Write accesses to HPICregister (see Note 2)19ns18H+10 ns26H+10 ns10H+10td(HCS-HRDY) Delay time, HCS low/high to HRDY low/high 15 nstd(COH-HYH) Delay time, CLKOUT high to HRDY high 2 nstd(COH-HTX) Delay time, CLKOUT high to HINT change 5 nsNOTES: 1. The HRDY output is always high when the HCS input is high, regardless of DS timings.2. This timing applies when writing a one to the DSPINT bit or HINT bit of the HPIC register. All other writes to the HPIC occurasynchronously, and do not cause HRDY to be deasserted.† DS refers to the logical OR of HCS, HDS1, and HDS2.‡ HDx refers to any of the HPI data bus pins (HD0, HD1, HD2, etc.).§ DMAC stands for direct memory access (DMA) controller. The HPI8 shares the internal DMA bus with the DMAC, thus HPI8 access times areaffected by DMAC activity. GPIO refers to the HD pins when they are configured as general-purpose input/outputs.6H+10nsApril 1999 − Revised October 2008SPRS082F79