处于手动模式下的 SG2 会生成连续脉冲，用户可以使用 ADSR 注释启用和禁用该脉冲。这意味着在手动模式脚本的开头和结尾处写入 ADSR 注释。请参阅节 3.1。此处不提供重启和延音计时器。

在手动模式下，对生成的脉冲每秒采样的样本数根据工作采样频率确定。例如...

...表示在一秒钟之内有 96K 个样本。

在手动模式下，每个脉冲跨越一秒，然后重复。手动模式在进行频率扫描时会出现混叠。请参阅下面的公式以生成干净的信号。这些公式可推导出发生混叠的样本、每个脉冲所需的样本数以及每个频率上升的时间。

这组公式适用于所有 SG2 模式。

对手动模式编程时，首先执行 ADSR 确认脚本，然后，执行其他 ADSR 参数，并在手动模式脚本的最后执行 ADSR 启用命令。

# 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) ################################################################### 
#manual mode example script
#acknowledge ADSR engine then enable it with x01 at the end of the script		
w a0 00 00	# locate page x00
w a0 01 01	# device reset
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 SG2 only
	
#Using chirp start frequency formula	
w a0 00 17  # locate page 0x17	
w a0 7c 02 18 2a 47  # SG2 start frequency at 1 KHz
	
#Using chirp delta frequency formula	
w a0 00 18  # locate page 0x18		
w a0 08 00 00 00 44 a1  #delta frequency of 0.5 Hz not causing aliasing	
	
#Acknowledge ADSR envelope	
w a0 00 1c  # locate page 0x1c	
w a0 40 00 00 00 00  # ADSR note, set 0 when powering 	
                     # up dac and set it to 1 to enable chirp	
	
#Set sustain and restart timer the same	
w a0 50 00 00 00 00  # restart_timer	
w a0 54 00 00 00 00  # sustain_timer	
	
w a0 00 17	# locate page 0x17
w a0 74 00 00 00 00  # power up delay	
	
#SG2 channel selection and amplitude level configuration 	
w a0 00 11 # locate page 0x11	
w a0 70 40 00 40 00  # OUT1
#w a0 74 40 00 40 00 # OUT2	
	
#Output configuration 	
w a0 00 00	# locate page 0
w a0 76 0c	# enable OUT1
w a0 78 40	# enable all DACs
	
#Turn on ADSR envelope	
w a0 00 1c          #locate page 1c	
w a0 40 00 00 00 01 # ADSR note, set 0 when powering 	
                    # up DAC and set it to 1 to enable chirp	
                    # for manual mode	

图 4-4 SG2 手动模式范围捕获：2Vrms 满量程时对 1KHz 信号进行 0.5Hz 扫描