连续脉冲模式 (CPM) 下的 SG2 会生成具有定义的重启和延音时间间隔的可重复脉冲。这两个计时器是根据工作采样率 fs 每秒的样本数进行配置的。请参阅表 3-3。

如果在延音时间间隔结束之前达到奈奎斯特频率 fs/2，则 CPM 中的 SG2 会出现混叠。可以使用节 4.4.1 中的时序公式生成可接受的最终频率以避免混叠。这些公式有助于选择低于奈奎斯特点的可接受终止频率。

必须在 CPM 的其他 ADSR 参数之前执行 ADSR 注释确认脚本。但是，CPM 脚本末尾不需要 ADSR 启用脚本。

# Key: w a0 XX YY ==> write to I2C address 0xa0, to register 0xXX, data 0xYY 
# # ==> comment delimiter 
#
#The following list gives an example sequence of items that must be #executed in the time between powering the device up and reading data #from the device. Note that there are other valid sequences depending #on which features are used.
#See the corresponding EVM user guide for jumper settings and audio #connections.
#
# Line-Out Fully-Differential 2-channel : OUT1P_M- Ch1, OUT2P_M- Ch2. 
# FSYNC = 48 kHz (Output Data Sample Rate), BCLK = 12.288 MHz (BCLK/FSYNC = 256) ################################################################### 

#Continuous pulse mode script	
#adsr note at the start needed
#no asdr note at the end needed 	
	
w a0 01 01	# device reset
	
w a0 00 00	# locate page 0x00
w a0 02 09	# come out of sleep mode with VREF and DREG up
	
w a0 00 01	# locate page 0x01
w a0 2d 04	# enable chirp only
	
w a0 00 17	# locate page 0x17
w a0 7c 14 f1 a6 c6 # 10kHz chirp start frequency	
	
	
w a0 00 18	# locate page 0x18
w a0 08 00 00 00 00	# chirp delta frequency of 0 Hz
	
w a0 00 1c	# locate page 0x1c
w a0 40 00 00 00 00	# adsr_note
	
#restart	
#w a0 50 00 00 bb 80     #48k samples for 1s	
w a0 50 00 00 12 c0 # 100ms default	
	
#sustain	
#w a0 54 00 00 5d c0 	#24000 samples at 500ms
w a0 54 00 00 01 e0 #10ms default	
	
#attack	
w a0 58 00 44 52 3f	# default with k=0.00417 @10k.
#w a0 58 00 03 6a 83	# 100ms with k=0.0002085 @10k.
	
#sustian level	
#w a0 64 20 00 00 00 # sustain lvl at k=0.5 	
	
#decay timer	
#w a0 60 ff bb ad c1 #5ms	

#channel selection	
w a0 00 11	#locate page 0x11
w a0 70 40 00 40 00	# OUT1
#w a0 74 40 00 40 00	# OUT2
	
w a0 00 00	# locate page 0x00
w a0 76 0c	# enable 2 DAC channels
w a0 78 40	# enable DAC

图 4-5 SG2 连续脉冲模式示波器捕获：2Vrms 满量程时的 10KHz 信号