4

4530H–BCD–09/09

T6818

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

n. u.

n. u.n. u.n. u.n. u.n. u.

OCS

n. u.n. u.

CS

DI

CLK

DO

TP

S1L

S1H

S2L

S2H

S3L

S3Hn. u.

n. u.n. u.n. u.n. u.n. u.

SCD

OPL

PSF

01

2

3

45

6

7

8

9

101112

13

14

15

Table 3-1.

Input Data Protocol

Bit

Input Register

Function

0SRR

Status register reset (high = reset; the bits PSF, OPL and SCD 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

n. u.

Not used

8

n. u.

Not used

9

n. u.

Not used

10

n. u.

Not used

11

n. u.

Not used

12

n. u.

Not used

13

OCS

Overcurrent shutdown (high = overcurrent shutdown is active)

14

n. u.

Not used

15

n. u.

Not used