Z8FS021 Datasheet, PDF (52/68 Pages) Zilog, Inc. – Select from an assortment of lenses and pyroelectric sensors to best fit your application

ZMOTION^® Intrusion Detection
Product Specification
44
Bit
Field
Control
Address
Table 28. PIR DC Signal Level
(ePIR_Signal_DC)
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
PIR Signal DC
Read
FCH
FDH
PIR Signal DC (Bits 15–0)
Controlled by the PIR Engine.
• These registers contain the last PIR signal DC Level calculated by the Engine. Each time the Engine
generates new control limits it will place the DC component level in these registers.
• Note: The 16 bit value provided by these two 8 bit registers must be read as an atomic operation by
the application. This can be ensured by either using the CPU's ATM instruction or by disabling
interrupts while reading the two 8 bit registers.
Table 29. PIR Extended Detection Sensitivity Level
(ePIR_Extended_Sense)
Bit
7
6
5
4
3
2
1
0
Field
PIR Extended Detection Sensitivity
Control
Read/Write
Address
FEH
Extended Detection Sensitivity (Bits 7–0)
Controlled by the application.
• This register determines how sensitive the Extended Detection part of the Engine is to fast or slow
speed targets in the PIR field of view. A lower number makes the extended detector more sensitive,
at the cost of potential false motion events. The valid range is 1 (most sensitive) to 255 (least
sensitive) with typical values between 6 and 25. Related control features include the PIR Extended
Detection Level (PIR_SC0) and the PIR Extended Detection Debounce Timeout.
PS028806-0315
Advanced API Register Set