SPI communication interface

AN4290

10/16

DocID024501 Rev 2

Releasing the failure flags (GetStatus command)

All the failure flags in the STATUS register of the device are latched when the respective

alarm condition is triggered. In this way, the occurrence of a temporary failure is stored into

the status register and the user is warned about it. The flags can be released through the

GetStatus command.

The command byte is described in Table 5.

The command does not need any argument and generates a response byte sequence

containing the STATUS register value (most significant byte first) and releases all the

latched failure flags. The response is generated before releasing the flags, so the returned

STATUS value still contains all the failure information.

The failure flags are cleared as soon as the GetStatus command byte is received as shown

in Figure 7.

Figure 7. GetStatus command and failure flag clearing

The response corresponds to the value of the STATUS register after the GetStatus

command has been received and decoded. If the register value changes later, the response

is not updated accordingly.

The STATUS register can also be read using the GetParam command; in this case the

failure flags are not released.

Table 5. GetStatus byte command

Bit #

7

654

321

0

1

011

000

0

From MCU (MOSI)

!

GetStatus

NOP

NOP

To MCU (MISO)

FLAG

output

Unknown

STATUS

(byte 1)

STATUS

(byte 0)

Failure flags are cleared

AM16751v1