Z8FS040BSB20EG Zilog, Z8FS040BSB20EG Datasheet - Page 34

• Manufacturer Part Number: Z8FS040BSB20EG
• Description: IC MCU 4KB FLASH IRDA 8SOIC
• Manufacturer: Zilog
• Series: ZMOTION™r

Specifications of Z8FS040BSB20EG

• Applications: Infrared Motion Detection
• Core Processor: eZ8
• Program Memory Type: FLASH (4 kB)
• Controller Series: Z8 Encore! XP®
• Interface: IrDA, UART/USART
• Number Of I /o: 5
• Voltage - Supply: 2.7 V ~ 3.6 V
• Operating Temperature: -40°C ~ 105°C
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (0.154", 3.90mm Width)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Ram Size: -
• Other names: 269-2512

Address
PIR Advanced Status/Control Register 0 (ePIR_ASC0)
Buffer Refresh (Bit 4)
New Sample (Bit 3)
PS028506-1110
Control
Field
Bit
Uses fast fill algorithm to quickly refill the motion detection buffers.
Controlled by application
This bit is used to restart motion detection by quickly reinitializing and refilling the motion detection
constructed sample buffers. This can be used as a method to restore motion detection after waking up
from sleep mode or it can be used to help ignore external events that may cause false detections.
Waking up from Sleep Mode:
If this bit is set when the EPIR_INIT macro is executed the Engine re-fills the constructed sample buffers
with a fast fill algorithm that allows it to quickly restore motion detection. Typically, a simple external
wake-up circuit would be implemented that provides an unqualified motion detection signal to wake up
the MCU from Sleep mode (SMR). Upon SMR, the application would set the Buffer Refresh bit, execute
EPIR_INIT, and then continue with normal motion detection functions for some period of time before
returning to Sleep mode. By setting this bit prior to EPIR_INIT, the Engine buffers are filled much faster
enabling it to analyze the original signal seen by the external wake up circuit and determine if it is ‘real’
motion.
Ignoring False Detection Events:
If the MCU is used to control external components (LED’s, relays, Lights, Triac’s, etc) a fluctuation on
the power supply can be created as the external device is turned on or off. The Buffer Refresh bit can
be used to ignore any false detection that could be created by these fluctuations. When the external
device is turned on or off, the application can set the Buffer Refresh bit to effectively reset the motion
detection history and therefore ignore any effect from the external device.
New sample available from PIR Signal High/Low register
Set by PIR engine, cleared by application
This bit indicates that the PIR engine has a new sensor signal input sample available that may be read
by the application. This status is available as an advanced feature as the application is not normally
required to read the sampled PIR sensor signal. The application must clear this bit when the sample has
been read.
Reserved
7
0
Reserved
6
0
Reserved
5
0
PRELIMINARY
Refresh
Buffer
R/W
4
F0H
Sample
New
R/W
ZMOTION
3
TM
Origin
MD
R
Detection and Control Family
2
Product Specification
EM Noise
Detected
R/W
1
Transient
Detected
R/W
EM
0
29