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AS1116

Datasheet - D e t a i l e d D e s c r i p t i o n

Serial Interface

The AS1116 contains a 16bit SPI interface to access the internal data and control registers of the device (see Digit- and Control-Registers

on page 11)

. The SPI interface is driven with the rising edge of SCL. A falling edge on LD signal indicates the beginning of an access on the

SPI interface, the rising edge on LD determines an access on SPI. An access must consist of exactly 16bits for write operation and 8bits for read

operation. Timing restrictions on the SPI interface pins are defined in Figure 19.

Table 6

shows the structure of the 16bit command word for writing data. The bits D0 to D7 are the data information, bits D8 to D12 are the

address bits, D13 is set to ‘0’, bit D14 is defining the read (D14 = ‘1’) or the write (D14 = ‘0’) configuration and bit D15 is a don’t care bit.

In Table 7 on page 11 the 8bit command word for the read operation can be found.

Bit D0 (write operation) or bit D8 (read operation) is the first bit to shift into the SPI interface after the falling edge of LD. Bit D15 is the last bit to

write to SPI before rising edge of LD.

At a read operation an 8bit operation is executed (see Figure 18). At the first rising edge of SCL after the rising edge of LD D7 of addressed

register is written to SDO pin. At the next rising edge of SCL D6 is written to SDO pin. LD must be kept high during reading data from a internal

data or control register of AS1116.

Figure 17. Write operation

Figure 18. Read operation

Table 6. 16-Bit Serial Data Format

D0

D1

D2

D3

D4

D5

D6

D7

D8

D9

D10

D11

D12

D13

D14

D15

LSB

Data

MSB

Register Address (see Table 7)

0

R/W

X

1

9

8

16

D3

D4

D5

D6

D7

D1

D2

D0

SCL

LD

SDI

D11 D12 D13 D14 D15

D9

D10

D8

SDO

D3

D4

D5

D6

D7

D1

D2

D0

D11 D12 D13 D14 D15

D9

D10

D8

1

9

8

16

D11 D12 D13 D14 D15

D9

D10

D8

SCL

LD

SDI

D4

D3

D2

D1

D0

D6

D5

D7

SDO