AS8221

Datasheet - Application In form atio n

www.austriamicrosystems.com/flexray/AS8221

Revision 1.7

23 - 42

9.4.6 Error Flag (ERROR)

The ERROR is signalled on the ERRN pin according to Table 6 and Table 8.

The flag is set if at least one of the error flags in chapters 9.4.2 to 9.4.5 is set. The flag will be reset if none of the flags in chapters 9.4.2 to 9.4.5

is set.

9.5 Status Flags

9.5.1 Local Wake Flag (LWAKE)

See chapter 8.7 Wake-Up Events on page 16

9.5.2 Remote Wake Flag (RWAKE)

see chapter 8.7 Wake-Up Events on page 16

9.5.3 Power on Flag (PWON)

The PWON is set leaving the POWER-OFF state and it is reset entering a low-power mode after a non-low-power mode.

9.6 Error Flags and Status Flags Read-Out

The readout mechanism consists of two information groups:

1. Error read-out

2. Status information read-out

The read-out mechanism as serial transmission on Pin EN and ERRN:

The error flags and the status flags can be read-out by applying a clock signal to pin EN in a non-low-power mode. A falling edge on pin EN starts

the read-out loading the content of the error/status flag into the shift register and signaling the error flag on the ERRN pin. On the second falling

device enters the operation mode selected by the host pins.

Figure 10. Timing of the Read-out Mechanism

Table 9. Read-out Mechanism and Transceiver States

State

Enabled / Disabled

NORMAL mode

Enabled

RECEIVE-ONLY mode

Enabled

STANDBY mode

Disabled

GO-TO-SLEEP mode

Disabled

SLEEP mode

Disabled

EN

ERRN

ERROR FLAG

Bit 0

Bit 1

Bit 2

ERRN

ERRN