Objective

Perform frequency offset calibration for DUT

Use DUT as RX mode, change the internal capacitance value of DUT, test the frequency offset with the reference signal source, find the minimum frequency offset capacitance value, and write it into DUT

Mode switch selection

Note

• Require UPT (model: T3 ), UPT is a calibrated Bluetooth TX signal source
• You may need modify the config file. The configuration items required for frequency offset calibration are the same as those for RF RX test

[RF_RX]
	# kHz, frequency deviation of BT Tester Box
	# kHz, 测试盒/UPT与精准源频率偏差，DUT需要进行补偿
	tester_freq_offset = 0
	
	# kHz, frequency deviation low limit for check
	# kHz, 频偏验证最小值，最终频偏值低于此值，会报错
	cfo_low_limit = -10
	
	# kHz, frequency deviation high limit for check
	# kHz, 频偏验证最大值，最终频偏值高于此值，会报错
	cfo_high_limit = 10
	
	# channel no when test，default is 36
	# 校准时，使用的channel编号，默认为 36
	channel = 36
	
	# Write capacity setting。 0:NOT Write	1:Write to Efuse  2:Write to Efuse and Nor
	# 校准完成后，电容值写入到哪里。 0:不写入  1:写入Efuse  2:写入Efuse+Nor
	cap_write_region = 2

	# Use rssi for check?
	# 使用信号强度验证？
	rssi_limit_enable = 1
	
	# dBm, rssi high limit for check
	# dBm, 信号强度验证最小值
	rssi_low_limit = -70
	
	# dBm, rssi low limit for check
	# dBm, 信号强度验证最大值
	rssi_high_limit = 20

Operation steps

• Powere on the UPT, and placed near DUT
• Start the BT Tester and enter the frequency offset calibration function
• Connect the DUT. After the DUT execute completed, the BT Tester obtains the frequency offset calibration result
• The BT Tester display the frequency offset and RSSI, and judges whether the frequency offset and RSSI are within the limited range
• If within the limit, broadcast PASS voice
• If outside the limits, broadcast FAIL voice