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4964B–AUTO–07/07

ATA6842

7.12

SPI Interface

The ATA6842 supports an 8-bit SPI interface to communicate with the microprocessor. The

MSB is transmitted first. There are two status registers (address 0xxxxx01 and 0xxxxx10) and

two control registers (address 1xxxxx01 and 1xxxxx10).

Table 7-5.

Status Register 0xxxxx01 Request by Microprocessor

Bit

Name

Meaning

Function

7

C1O

Comparator 1 output

0: comparator C1I below threshold

1: comparator C1I above threshold

6

EK15S

EK15 status

0: EK15 below threshold

1: EK15 above threshold

5

WLPS

Warnlamp polarity status

0: pin WLP = low

1: pin WLP = high

4

OTS

Overtemperature status

0: normal operation

1: overtemperature present or

overtemperature detection switched off

3

WDOK

Watchdog status

0: watchdog OK

1: watchdog failure

2:0

WDC(2:0)

Watchdog counter bit 2:0

Status of watchdog counter

Table 7-6.

Status Register 0xxxxx10 Request by Microprocessor

Bit

Name

Meaning

Function

7

WLNOC

Warnlamp overcurrent

0: no overcurrent

1: overcurrent

6

ONOC

OUTN overcurrent

0: no overcurrent

1: overcurrent

5

OPOC

OUTP overcurrent

0: no overcurrent

1: overcurrent

4

WLNCS

Warnlamp current status

0: current below threshold

1: current above threshold

3

ONCS

OUTN current status

0: current below threshold

1: current above threshold

2

OPCS

OUTP current status

0: current below threshold

1: current above threshold

1

WLNVS

Warnlamp voltage status

0: voltage below threshold

1: voltage above threshold

0

ONVS

OUTN voltage status

0: voltage below threshold

1: voltage above threshold