參數(shù)資料
型號: 37C672
廠商: SMSC Corporation
英文描述: ENHANCED SUPER I/O CONTROLLER WITH FAST IR
中文描述: 增強(qiáng)的超級I / O控制器,快速紅外線
文件頁數(shù): 112/173頁
文件大小: 965K
代理商: 37C672
3802 GROUP USER’S MANUAL
1-28
HARDWARE
Data bus
Count source
selection bit
“0”
“1”
PWM
prescaler pre-latch
PWM
register pre-latch
PWM
prescaler latch
PWM
register latch
Transfer control circuit
PWM register
1/2
XIN
Port P56 latch
PWM enable bit
Port P56
PWM prescaler
PULSE WIDTH MODULATION (PWM)
The 3802 group has a PWM function with an 8-bit resolution,
based on a signal that is the clock input XIN or that clock input di-
vided by 2.
Data Setting
The PWM output pin also functions as port P56. Set the PWM pe-
riod by the PWM prescaler, and set the period during which the
output pulse is an “H” by the PWM register.
If the value in the PWM prescaler is n and the value in the PWM
register is m (where n = 0 to 255 and m = 0 to 255) :
PWM period = 255 ! (n+1)/f(XIN)
= 51 ! (n+1)
s (when XIN = 5 MHz)
Output pulse “H” period = PWM period ! m/255
= 0.2 ! (n+1) ! m
s
(when XIN = 5 MHz)
PWM Operation
When bit 0 (PWM enable bit) of the PWM control register is set to
“1”, operation starts by initializing the PWM output circuit, and
pulses are output starting at an “H”.
If the PWM register or PWM prescaler is updated during PWM
output, the pulses will change in the cycle after the one in which
the change was made.
Fig. 26 Timing of PWM cycle
Fig. 27 Block diagram of PWM function
51 ! m ! (n+1)
255
s
T = [51 ! (n+1)]
s
PWM output
m: Contents of PWM register
n : Contents of PWM prescaler
T : PWM cycle (when X IN = 5 MHz)
FUNCTIONAL DESCRIPTION
相關(guān)PDF資料
PDF描述
37C67X ENHANCED SUPER I/O CONTROLLER WITH FAST IR
37C957FR ULTRA I/O CONTROLLER FOR PORTABLE APPLICATIONS
37FMA1-ABW31N SPECIAL SWITCH-PIEZO SWITCH, SPST, MOMENTARY, 0.2A, 24VDC, PANEL MOUNT-THREADED
37FML1-BEW31N SPECIAL SWITCH-PIEZO SWITCH, SPST, MOMENTARY, 0.2A, 24VDC, PANEL MOUNT-THREADED
37FML2-ACW21N SPECIAL SWITCH-PIEZO SWITCH, SPST, MOMENTARY, 1A, 24VDC, PANEL MOUNT-THREADED
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
37C67X 制造商:SMSC 制造商全稱:SMSC 功能描述:ENHANCED SUPER I/O CONTROLLER WITH FAST IR
37C-6BH-5-5 制造商:Birtcher Products 功能描述:
37C72U-185 制造商:White-Rodgers 功能描述:
37C73U-170 制造商:White-Rodgers 功能描述:
37C73U-171 制造商:White-Rodgers 功能描述: