Analog Integrated Circuit Device Data

Freescale Semiconductor

17

33884

FUNCTIONAL DEVICE OPERATION

LOGIC COMMANDS AND REGISTERS

NORMAL AND PERIODIC

Bits [16:15] identify one of the three operating modes:

Normal, Polling, and Polling + INT Timer. The remaining bits

identify the device as the Master or a Slave, whether the

device has an interrupt that has not been cleared, and the

state of all the inputs.

MASL– MASTER/SLAVE IDENTIFICATION FLAG

This flag is the same as the state of the MASL pin. It

provides software identification of the configuration of each

IC.

INT – EXTERNAL INTERRUPT FLAG

This flag identifies this particular IC as the initiator of an

external interrupt. It is the inverse of INT.

These twelve flags indicate the state of all switch inputs:

TRI-STATE

All Tri-State inputs have their wetting and sustain currents

disabled. By definition, all disabled inputs return the following

value for the switch state whenever SPI data is exchanged:

Table 19. Normal and Periodic

MSB

LSB

Mode

16

15

14

13

12

11

10

9

8

7

6

5

4

3

2

1

Normal

0

1

MASL

INT

SG6

SG5

SG4

SG3

SG2

SG2

SG1

SP3

SP2

SP1

SB2

SB1

Polling

1

0

x

—

—

Polling + INT Timer

1

1

INT

—

—

Note: The SPI response given while sending the command to exit Sleep mode should be ignored due to unknown power-up state.

Table 20. MASL Bit Definition

MASL

Device is a:

0

Slave

1

Master

Table 21. MASL Bit Definition

MASL

16

15

14

13

Type of Interrupt

Normal

0

1

x

0

Nothing Happened

—

—

—

1

Switch Interrupt

Polling

1

0

x

x

—

1

1

x

0

Nothing Happened

Polling + INT

Timer

—

—

—

1

Wake up Interrupt

SG[6:1] = Switch-to-ground flag

SB[2:1] = Switch-to-battery flag

SP[4:1] = Programmable switch flag

Table 22. Switch State Bit Definition

SGx, SBx, SPx

External

Switch is:

Mode

Input States Latched:

0

Open

Normal

At the moment CS

transitions to logic 0

1

Closed

Polling

Table 23. Tri-State Bit Definition

SGx, SBx, SPx

External Switch is:

0

Tri-State