AMIS-52150 Datasheet, PDF (17/21 Pages) AMI SEMICONDUCTOR – Low-Power Transceiver with Clock and Data Recovery

AMIS−52150
Table 22. DATA AND CLOCK RECOVERY CONTROL REGISTERS (continued)
Register (HEX)
Name
Bits
States
Comments
0x12
STOP CHECK
0, 1
00
Stop Check Bits: Disabled
01
Stop Check Bits: 2
10
Stop Check Bits: 4
LOOPCLAMP
11
Stop Check Bits: 8
2, 3
00
Loop Clamp Value is: BaudClk/8
01
Loop Clamp Value is: BaudClk/16
10
Loop Clamp Value is: BaudClk/32
11
Loop Clamp Value is: BaudClk/64
FREERUN
4
0
Phase Alignment Enabled
1
Phase Alignment Disabled
CDR RESET
5
0
CDR Reset Disabled
1
CDR Reset Enabled
AUTO/MANUAL RESET
6
0
POR Reset (Auto)
1
CDR Reset Enabled (Manual)
SAMPLE WINDOW
7
00
Sampling Starts with Bit Start Edge
00
Sampling Centered around Bit Center
The clock and data recovery function is dependent on the
receiver’s ability to recover the data from the incoming RF
signal. There exists a technique to test the clock and data
recovery function without having to set up the receiver to
receive data. This is a test mode that allows an input data
stream (square wave at 1/2 the data rate) on the RSSI pin,
with the recovered clock data appearing on the CLKOUT
pin and the recovered data appearing on the TX/RX pin,
respectively. Once the AMIS−52150 is configured for clock
and data recovery, the register shown in Table 23 can be used
to define the test mode operation.
Table 23. CLOCK AND DATA RECOVERY TEST MODE
Register (HEX)
0x1d
Clock and Data Recovery Test Control Register
Binary Code
HEX Code
Comments
00001110
0x0e
Normal RSSI Digital Input
00001111
0x0f
CDR Start Bit Digital Input to RSSI
Wake-up Function
Ultra-low power applications can take advantage of the
wake-up function of the AMIS−52150. The AMIS−52150
can be placed in a low power or “sleep” state until an
interrupt based on the programmable wake-up timer is
generated. This wakes up the transceiver, which then flags
the external microcontroller to perform the required
application-specific operations. The wake-up interrupt is
also generated based on detection of RF energy (Sniff
Mode). Communication with the microcontroller takes
place via the I²C bus. In addition, when the AMIS−52150 is
in the “sleep” state, the wake-up signal can be generated by
the microcontroller. Table 24 lists the registers associated
with the wake-up function.
Table 24. APPLICATION WAKE-UP CONTROL REGISTERS
Register (HEX)
Name
Bits
0x14
AW TIMER DIV
All
0x15
AW TIMER
All
0x17
PRE/POST AW DELAY
All
Comments
Divides the RC Oscillator to Form a Clock for the AW
Number of AW Clock Periods before a AW Wake-up
Number of CLKOUT Clock Periods before the TX/RX
Pin Goes Low for a AW Cycle
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