Intel 8XC196NP manual Single Transfer Mode Ptscb, Block Transfer Mode Ptscb, Ptscount = 09H

Models: Microcontroller 80C196NU 8XC196NP

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STANDARD AND PTS INTERRUPTS

Table 6-5. Single Transfer Mode PTSCB

Unused

Unused

PTSDST (HI) = 60H

PTSDST (LO) = 00H

PTSSRC (HI) = 00H

PTSSRC (LO) = 20H

PTSCON = 85H (Mode = 100, BW = 0, SI/SU = 0, DI/DU = 1)

PTSCOUNT = 09H

6.6.4Block Transfer Mode

In block transfer mode, an interrupt causes the PTS to move a block of bytes or words from one memory location to another. See AP-445, 8XC196KR Peripherals: A User’s Point of View, for ap- plication examples with code. Figure 6-13 shows the PTS control block for block transfer modes.

In this mode, each PTS cycle consists of the transfer of an entire block of bytes or words. Because a PTS cycle cannot be interrupted, the block transfer mode can create long interrupt latency. The worst-case latency could be as high as 500 states, if you assume a block transfer of 32 words from one external memory location to another, using an 8-bit bus with no wait states. See Table 6-4 on page 6-10 for execution times of PTS cycles.

The PTSCB in Table 6-6 sets up three PTS cycles that will transfer five bytes from memory loca- tions 20–24H to 6000–6004H (cycle 1), 6005–6009H (cycle 2), and 600A–600EH (cycle 3). The source and destination are incremented after each byte transfer, but the original source address is reloaded into PTSSRC at the end of each block-transfer cycle. In this routine, the PTS always gets the first byte from location 20H.

Table 6-6. Block Transfer Mode PTSCB

Unused

PTSBLOCK = 05H

PTSDST (HI) = 60H

PTSDST (LO) = 00H

PTSSRC (HI) = 00H

PTSSRC (LO) = 20H

PTSCON = 17H (Mode = 000; DI, SI, DU, BW = 1; SU = 0)

PTSCOUNT = 03H

6-23

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Intel 8XC196NP, 80C196NU manual Single Transfer Mode Ptscb, Block Transfer Mode Ptscb, Ptscount = 09H, Ptscount = 03H