AD转换（DA用pwm）
.................\17
.................\..\ExtDll.iex
.................\..\Last Loaded ex4-17.DBK
.................\..\STARTUP.A51
.................\..\STARTUP.LST
.................\..\STARTUP.OBJ
.................\..\STC15F2K.h
.................\..\adc.plg
.................\..\ex4-17
.................\..\ex4-17.BMP
.................\..\ex4-17.DSN
.................\..\ex4-17.M51
.................\..\ex4-17.hex
.................\..\ex4-17.lnp
.................\..\ex4-17.plg
.................\..\ex4-17.uvgui.Administrator
.................\..\ex4-17.uvopt
.................\..\ex4-17.uvproj
.................\..\ex4-17_uvopt.bak
.................\..\ex4-17_uvproj.bak
.................\..\main.LST
.................\..\main.OBJ
.................\..\main.c
.................\Thumbs.db
.................\ex4-18
.................\......\ExtDll.iex
.................\......\STARTUP.A51
.................\......\STARTUP.LST
.................\......\STARTUP.OBJ
.................\......\STC15F2K.h
.................\......\adc_int.plg
.................\......\ex4-18
.................\......\ex4-18.M51
.................\......\ex4-18.hex
.................\......\ex4-18.lnp
.................\......\ex4-18.plg
.................\......\ex4-18.uvgui.Administrator
.................\......\ex4-18.uvopt
.................\......\ex4-18.uvproj
.................\......\ex4-18_uvopt.bak
.................\......\ex4-18_uvproj.bak
.................\......\main.LST
.................\......\main.OBJ
.................\......\main.c