Echelon I/O Model Reference for Smart Transceivers and Neu Manuel d'utilisateur télécharger pdf (Page 121)

I/O Model Reference 111

Up to 255 bytes can be bi-directionally transferred at a time. This I/O model

depends on interrupts to process data at high speed and does not use the io_in()

and io_out() function calls. After transfer is initiated, control is returned to the

application immediately, and the application needs to poll the I/O model for

completion. Transfers can be suspended and resumed by disabling and enabling

interrupts. Turning off interrupts might be required when going off-line, or for

assuring that other time-critical application execution is not disturbed by

background interrupts. Additionally, transfers can be aborted.

[default] (CPOL = 1)

Present bit

Sample bit

Invert (CPOL = 0)

MISO

MOSI

msb lsbbit5 bit4bit6 bit2bit3 bit1

Figure 39. Transmission Timing for Clockedge(-) (CPHA : 0)

[default] (CPOL = 1)

Present bit

Sample bit

invert (CPOL = 0)

MISO

MOSI

msb lsbbit5 bit4bit6 bit2bit3 bit1

Figure 40. Transmission Timing for Clockedge(+) (CPHA : 1)

1 2 ... 116 117 118 119 120 121 122 123 124 125 126 ... 208 209

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Echelon I/O Model Reference for Smart Transceivers and Neu Manuel d'utilisateur Page 121