EM78808
8-bit Micro-controller
VII.10 Differential Energy Detector (DED)
EGIN1
DEDD
DED
EGIN2
EGCLK
DEDPWR DEDTHD
Fig.27 DED
The Differential Energy Detector is differential input level and zero crossing detector named as DED. It
can detect any incoming AC signal above its threshold level and output corresponding zero-crossing frequency
pulse. For this energy detector, the user can set it’s minimum detection threshold level at –35dBm or –45dBm
by DEDTHD bit. All the minimum detection value can be achieved under input capacitor more than 4700pF and
input resistor around 100k ohms. The energy detector has power control by IOCE PAGE2 bit 1 (DEDPWR).
Register bits of Energy Detector :
Register bits
Descriptions
RE bit 7 (DEDD)
IOCE PAGE2
bit 5 (EDGE)
IOCE PAGE2
bit 4 (WUEDD)
RE PAGE1 bit 6 (DED)
IOCE PAGE2 bit6
(DED)
DEDD : Output data of DED
EDGE : edge control of DED output data
1/0 => Falling edge trig. / Rising edge and Falling edge trig.
WUEDD : Wake-up control of DED output data
1/0 => enable/disable
DED : Interrupt flag of DED output data
DED : Interrupt mask of DED output data
1/0 ꢂenable/disable interrupt of DED output data
DEDTHD : Minimum detection threshold of DED
0/1 ꢂ-45dBm/-35dBm
IOCE PAGE2 bit 0
(DEDTHD)
IOCE PAGE2 bit 1
(DEDPWR)
DEDPWR : Power control of DED
0/1 ꢂpower off/power on
IOCE PAGE2 bit 2
(DEDCLK)
DEDCLK : operating clock of DED
0 : low frequency clock
1 : high frequency clock
VIII. Absolute Operation Maximum Ratings
RATING
DC SUPPLY VOLTAGE
INPUT VOLTAGE
SYMBOL VALUE
UNIT
V
V
℃
VDD
Vin
Ta
-0.3 To 6
-0.5 to VDD +0.5
0 to 70
OPERATING TEMPERATURE RANGE
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* This specification is subject to change without notice.
8/1/2004 (V3.1)
49
ELAN [ ELAN MICROELECTRONICS CORP ]
