AS8221

Datasheet - Application In form atio n

www.austriamicrosystems.com/flexray/AS8221

Revision 1.4

20 - 41

Notes:

remain in GO-TO-SLEEP.

2. If wake-up flag is set INH2=H otherwise INH2=floating.

3. Starting from SLEEP, if the wake-up flag is set, the device enters STANDBY regardless the host pins state and UV flags. Starting from

SLEEP, if the wake-up flag is not set, the only operating mode that can be entered through host pins are the non-low-power modes.

9.2.1 Operating Mode Transitions

Table 7. Transition Table

Transition

Event

Under Voltage Flag

Wake Flag

Host Input

Remarks

Start Point

Destination

STBN

EN

NORMAL

RECEIVE-ONLY

S

L

L

L

X

H

(1) H

→L

STANDBY

U

L

L

(1) L

→H(2) X→LH

H

GO-TO-SLEEP

S

L

L

L

(2) X

→L(1) H→LH

sleep timer

enabled

SLEEP

U(1) L

→HL

L

(2) X

→LH

H

U

L

(1) L

→H(2) X→LH

H

RECEIVE-

ONLY

NORMAL

S

L

L

L

X

H

(1) L

→H

STANDBY

S

L

L

L

(2) X

→L(1) H→LL

UL

L

(1) L

→H(2) X→LH

L

SLEEP

U(1) L

→HL

L

(2) X

→LH

L

U

L

(1) L

→H

L

(2) X

→LH

L

STANDBY

NORMAL

UL

L

(1) H

→LL

H

H

WL

L

(2) H

→L(1) L→HH

H

RECEIVE-ONLY

SL

L

L

X

(1) L

→HL

UL

L

(1) H

→LL

H

L

WL

L

(2) H

→L(1) L→HH

L

GO-TO-SLEEP

S

L

L

L

L

L

(1) L

→H

sleep timer

enabled

S

L

L

L

H

L

(1) L

→H

sleep timer

disabled

UL

L

(1) H

→LL

L

H

sleep timer

enabled

WL

L

(2) H

→L(1) L→HL

H

sleep timer

disabled

SLEEP

U(1) L

→HL

L

(2) X

→LL

L

U(1) L

→HL

H

L

X

X

U

L

(1) L

→H

L

(2) X

→LL

L

STANDBY

WL

L

(2) X

→L(1) L→HL

L

UL

L

(1) L

→H(2) X→LL

L

UL

L

(1) H

→LL

L

L

SL

L

H

L

(1) L

↔HX

S

L

L

H

L

X

(1) L

↔H