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ATA5723C/ATA5724C/ATA5728C [DATASHEET]

9248D–RKE–10/14

10.2

Controlled Noise Suppression by the Microcontroller

Digital noise appears at the end of a valid data stream if the bit Noise_Disable (see Table 11-9 on page 24) in the OPMODE

register is set to 0. To suppress the noise, the pin POLLING/_ON must be set to low. The receiver remains in receiving

mode. The OFF command then causes a change to start-up mode. The programmed sleep time (see Table 11-7 on page 24)

is not executed because the level at pin POLLING/_ON is low; however, the bit check is active in this case. The OFF

command also activates the bit check if the pin POLLING/_ON is held to low. The receiver changes back to receiving mode

if the bit check was successful. To activate the polling mode at the end of the data transmission, the pin POLLING/_ON must

be set to high. This way of suppressing the noise is recommended if the data stream is not Manchester or bi-phase coded.

Figure 10-4. Controlled Noise Suppression

POLLING/_ON

(DATA_CLK)

Serial bi-directional

Data Line

Data

Preburst

Receiving Mode

Receiving Mode

Start-up

Mode

Sleep

Mode

Bit-check

Mode

Bit-check

Mode

Bit Check ok

Data

Digital Noise

Digital Noise

Preburst

OFF-command

Bit Check ok