Z8FS040 Datasheet, PDF (17/56 Pages) Zilog, Inc. – ZMOTION Detection and Control Family Featuring Zilog’s PIR Technology

ZMOTION^TM Detection and Control Family
Product Specification
ADC
Zilog’s PIR technology requires exclusive access to the ADC peripheral in order to detect
motion. However, ADC conversions can be requested by the application through the API (PIR
Status/Control Register 3). If it is necessary for the user application to utilize the ADC
peripheral directly, the PIR engine must first be disabled via the PIR Engine Enable Register in
the API. Motion detection is not possible while the PIR engine is disabled. When the user
application is finished with the ADC peripheral, it must re-enable the PIR engine.
8 Pin Device: PA3 (ANA2) is reserved as the analog ADC input from the pyroelectric sensor.
Therefore ANA2 is not available for user applications. Additionally ANA3 is used for second
sensor input in dual pyro mode. All other channels are available to the user application.
ADC Channel
0
1
2
3
Available to Application
Yes
Yes
No
Only in Single Pyro Mode
20 Pin Device: PB2 (ANA2) is reserved as the analog ADC input from the pyroelectric sensor.
Therefore ANA2 is not available for user applications. Also, ANA3 and ANA6 are not available
since PB3 (ANA3) must be tied directly to PC2 (ANA6/ V_REF). PC2 is configured as V_REF output
by the PIR engine. In dual pyro mode ANA3 is used for second sensor input – rather than
being tied to V_REF and therefore ANA6/ V_REF becomes available. All other channels are
available to the user application.
ADC Channel
0
1
2
3
4
5
6
Available to Application
Yes
Yes
No
No
Yes
Yes
Only in Dual Pyro Mode
28 Pin Device: PB2 (ANA2) is reserved as the analog ADC input from the pyroelectric sensor.
Therefore ANA2 is not available for user applications. Also, ANA3 is not available since it is
tied directly to PB5/ V_REF. PB5 will be configured as V_REF output by the PIR engine. In dual pyro
mode ANA3 is used for second sensor input – rather than being tied to V_REF and therefore PB5
becomes available. All other channels are available to the user application.
ADC Channel
0
1
2
3
4
5
6
7
Available to Application
Yes
Yes
No
No
Yes
Yes
Yes
Yes
PS028506-1110
PRELIMINARY
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