欢迎访问ic37.com |
会员登录 免费注册
发布采购

7906 参数 Datasheet PDF下载

7906图片预览
型号: 7906
PDF下载: 下载PDF文件 查看货源
内容描述: 16位单片机 [16-BIT SINGLE-CHIP MICROCOMPUTER]
分类和应用: 计算机
文件页数/大小: 531 页 / 3056 K
品牌: RENESAS [ RENESAS TECHNOLOGY CORP ]
 浏览型号7906的Datasheet PDF文件第303页浏览型号7906的Datasheet PDF文件第304页浏览型号7906的Datasheet PDF文件第305页浏览型号7906的Datasheet PDF文件第306页浏览型号7906的Datasheet PDF文件第308页浏览型号7906的Datasheet PDF文件第309页浏览型号7906的Datasheet PDF文件第310页浏览型号7906的Datasheet PDF文件第311页  
A-D CONVERTER  
12.3 A-D conversion method  
12.3 A-D conversion method  
The A-D converter compares the comparison voltage (Vref), which is internally generated according to the  
contents of the successive approximation register, with the analog input voltage (VIN), which is input from  
the analog input pin (AN ). By reflecting the comparison result on the successive approximation register, VIN  
i
is converted into a digital value. When a trigger is generated, the A-D converter performs the following  
processing:  
Determining bit 9 of the successive approximation register  
The A-D converter compares Vref with VIN. At this time, the contents of the successive approximation  
register is 1000000000 (initial value).  
2
Bit 9 of the successive approximation register depends on the comparison result as follows:  
When Vref < VIN, bit 9 = 1”  
When Vref > VIN, bit 9 = 0”  
Determining bit 8 of the successive approximation register  
After setting bit 8 of the successive approximation register to 1,the A-D converter compares Vref with  
V
IN. Bit 8 depends on the comparison result as follows:  
When Vref < VIN, bit 8 = 1”  
When Vref > VIN, bit 8 = 0”  
Determining bits 7 to LSB of the successive approximation register  
Operation is performed for each of bits 7 to 0 in the 10-bit resolution mode.  
Operation is performed for each of bits 7 to 2 in the 8-bit resolution mode.  
When the LSB is determined, the contents of the successive approximation register (in order words,  
conversion result) are transferred to the A-D register i.  
V
ref is generated according to the latest contents of the successive approximation register. Table 12.3.1 lists  
the relationship between the successive approximation registers contents and Vref. Tables 12.3.2 and 12.3.3  
list the changes of the successive approximation register and Vref during the A-D conversion, respectively.  
Figure 12.3.1 shows the ideal A-D conversion characteristics in the 10-bit resolution mode.  
Table 12.3.1 Relationship between successive approximation register’s contents and Vref  
Successive approximation registers contents: n  
V
ref (V)  
0
0
V
REF  
× (n 0.5)  
1 to 1023  
1024  
V
REF: Reference voltage  
7906 Group Users Manual Rev.2.0  
12-12  
 复制成功!