4

4531G–BCD–07/09

ATA6829

3.

Functional Description

3.1

Serial Interface

Data transfer starts with the falling edge of the CS signal. Data must appear at DI synchronized

to CLK and are accepted on the falling edge of the CLK signal. LSB (bit 0, SRR) has to be trans-

ferred first. Execution of new input data is enabled on the rising edge of the CS signal. When CS

is high, pin DO is in tri-state condition. This output is enabled on the falling edge of CS. Output

data will change their state with the rising edge of CLK and stay stable until the next rising edge

of CLK appears. LSB (bit 0, TP) is transferred first.

Figure 3-1.

Data Transfer

SRR

LS1HS1LS2HS2LS3

HS3

PL1

PH1

PL2

PH2

PL3

PH3

OLD

OCSSI

CS

DI

CLK

DO

TP

S1L

S1H

S2L

S2H

S3L

S3Hn. u.

n. u.n. u.n. u.n. u.n. u.OVL

INH

PSF

012

3

45

67

8

910

11

12

13

14

15

Table 3-1.

Input Data Protocol

Bit

Input Register

Function

0SRR

Status register reset (high = reset; the bits PSF and OVL in the output

data register are set to low)

1

LS1

Controls output LS1 (high = switch output LS1 on)

2

HS1

Controls output HS1 (high = switch output HS1 on)

3

LS2

See LS1

4

HS2

See HS1

5

LS3

See LS1

6

HS3

See HS1

7

PL1

Output LS1 additionally controlled by PWM Input

8

PH1

Output HS1 additionally controlled by PWM Input

9

PL2

See PL1

10

PH2

See PH1

11

PL3

See PL1

12

PH3

See PH1

13

OLD

Open load detection (low = on)

14

OCS

Overcurrent shutdown (high = overcurrent shutdown is active)

15

SI

Software inhibit; low = standby, high = normal operation

(data transfer is not affected by standby function because the digital part

is still powered)