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M37270EFSP 参数 Datasheet PDF下载

M37270EFSP图片预览
型号: M37270EFSP
PDF下载: 下载PDF文件 查看货源
内容描述: 单片8位CMOS单片机结合闭合字幕解码器和屏幕显示控制器 [SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER with CLOSED CAPTION DECODER and ON-SCREEN DISPLAY CONTROLLER]
分类和应用: 解码器显示控制器瞄准线计算机
文件页数/大小: 95 页 / 1505 K
品牌: RENESAS [ RENESAS TECHNOLOGY CORP ]
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MITSUBISHI MICROCOMPUTERS  
M37270MF-XXXSP  
M37270EF-XXXSP, M37270EFSP  
SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER with CLOSED CAPTION DECODER  
and ON-SCREEN DISPLAY CONTROLLER  
PWM OUTPUT FUNCTION  
The M37270MF-XXXSP is equipped with eight 8-bit PWMs (PWM0-  
–PWM7). PWM0–PWM7 have the same circuit structure and an 8-  
bit resolution with minimum resolution bit width of 4µs (for f(XIN) =  
8 MHz) and repeat period of 1024µs.  
Figure 12 shows the PWM block diagram. The PWM timing generat-  
ing circuit applies individual control signals to PWM0–PWM7 using  
f(XIN) divided by 2 as a reference signal.  
(1) Data Setting  
When outputting PWM0–PWM7, set 8-bit output data in the PWMi  
register (i means 0 to 7; addresses 020016 to 020716).  
(2) Transmitting Data from Register to PWM circuit  
Data transfer from the 8-bit PWM register to 8-bit PWM circuit is  
executed at writing data to the register.  
The signal output from the 8-bit PWM output pin corresponds to the  
contents of this register.  
(3) Operating of 8-bit PWM  
The following is the explanation about PWM operation.  
At first, set the bit 0 of PWM mode register 1 (address 020A16) to “0”  
(at reset, bit 0 is already set to “0” automatically), so that the PWM  
count source is supplied.  
PWM0–PWM3 are also used as pins P04–P07, PWM4–PWM6 are  
also used as pins P00–P02, PWM7 is also used as pins P50, re-  
spectively. Set the corresponding bits of the port P0 direction regis-  
ter to “1” (output mode). And select each output polarity by bit 3 of  
the PWM mode register 1 (address 020A16). Then, set bits 7 to 0 of  
the PWM output control register 2 to “1” (PWM output).  
The PWM waveform is output from the PWM output pins by setting  
these registers.  
Figure 13 shows the 8-bit PWM timing. One cycle (T) is composed  
8
of 256 (2 ) segments. The 8 kinds of pulses relative to the weight of  
each bit (bits 0 to 7) are output inside the circuit during 1 cycle. Refer  
to Figure 13 (a). The 8-bit PWM outputs waveform which is the logi-  
cal sum (OR) of pulses corresponding to the contents of bits 0 to 7 of  
the 8-bit PWM register. Several examples are shown in Figure 13  
(b). 256 kinds of output (“H” level area: 0/256 to 255/256) are se-  
lected by changing the contents of the PWM register. A length of  
entirely “H” output cannot be output, i.e. 256/256.  
(4) Output after Reset  
At reset, the output of ports P00–P02 and P04–P07 is in the high-  
impedance state, port P50 outputs “L,” and the contents of the PWM  
register and the PWM circuit are undefined. Note that after reset, the  
PWM output is undefined until setting the PWM register.  
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