CMOSTEK CMT2250A, Руководство по настройке

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CMT2250A. The external MCU can produce the data packet with any length of preamble that is required.
3.4 Rx Early Exit
Rx Early Exit function allows the device to exit the RX state as soon as a certain number of packets defined by “Valid Reception”
have been successfully received and decoded. This function is only available in duty-cycle receive mode. It is designed to further
save the power consumption by shortening the receive time. The below are a few application examples.
3.4.1 Application Example 1: Fixed Duty with Rx Early Exit
Table 6. Fixed Duty with “Rx Early Exit = On” Configurations
Options Value
Sleep Time 5,000 ms
Rx Time 400 ms
Rx Time Ext NA
Wake-On Radio Off
Preamble NA
Rx Early Exit On
Valid Reception 1 packet
This example is based on the one descript in Chapter 3.3.1. When no signal is being transmitted, the device works in the fixed
duty mode. The Rx Time is 400 ms.
SLEEP SLEEP RX
(400 ms)
XTAL
(310 us)
SLEEP
(5,000 ms)
TUNE
(300 us)
XTAL
(310 us)
TUNE
(300 us)
RX
(400 ms)
time
Figure 15. Fixed Duty Operation
Because the Rx Early Exit function is turned on and the “Valid Reception” is set to 1 packet, the device automatically exits the RX
state as soon as 1 valid packet is successfully captured. As shown in the below figure, due to the happening of the early exit
event, the device only stays in the RX state for 160 ms in the current cycle, saving 240 ms from the original 400 ms.
SLEEP SLEEP
(5000 ms)
Early Exit
Data Packet
RX
(160 ms, saving 240 ms)
XTAL
(310 us)
TUNE
(300 us)
time
Data Packet
Figure 16. Fixed Duty with Rx Early Exit Operation