参数资料
型号: SST89E554A-40-C-NJ
厂商: SILICON STORAGE TECHNOLOGY INC
元件分类: 微控制器/微处理器
英文描述: 8-BIT, FLASH, 40 MHz, MICROCONTROLLER, PQCC44
封装: PLASTIC, MS-018AC, LCC-44
文件页数: 52/87页
文件大小: 996K
代理商: SST89E554A-40-C-NJ
56
Preliminary Specifications
FlashFlex51 MCU
SST89E554A / SST89V554A
2003 Silicon Storage Technology, Inc.
S71228-00-000
6/03
8.3.4 Pulse Width Modulator
The Pulse Width Modulator (PWM) mode is used to gener-
ate 8-bit PWMs by comparing the low byte of the PCA
timer (CL) with the low byte of the compare register
(CCAPnL). When CL < CCAPnL the output is low. When
CL
≥ CCAPnL the output is high. To activate this mode, the
user must set the PWM and ECOM bits in the module’s
CCAPMn SFR. (See Figure 8-5 and Table 8-7)
In PWM mode, the frequency of the output depends on the
source for the PCA timer. Since there is only one set of CH
and CL registers, all modules share the PCA timer and fre-
quency. Duty cycle of the output is controlled by the value
loaded into the high byte (CCAPnH). Since writes to the
CCAPnH register are asynchronous, a new value written to
the high byte will not be shifted into CCAPnL for compari-
son until the next period of the output (when CL rolls over
from 255 to 00).
To calculate values for CCAPnH for any duty cycle, use
the following equation:
CCAPnH = 256(1 - Duty Cycle)
where CCAPnH is an 8-bit integer and Duty Cycle is a
fraction.
FIGURE
8-5: PCA PULSE WIDTH MODULATOR MODE
TABLE
8-7: PULSE WIDTH MODULATOR FREQUENCIES
PCA Timer Mode
PWM Frequency
12 MHz
16 MHz
1/12 Oscillator Frequency
3.9 KHz
5.2 KHz
1/4 Oscillator Frequency
11.8 KHz
15.6 KHz
Timer 0 Overflow:
8-bit
15.5 Hz
20.3 Hz
16-bit
0.06 Hz
0.08 Hz
8-bit Auto-Reload
3.9 KHz to 15.3 Hz
5.2 KHz to 20.3 Hz
External Input (Max)
5.9 KHz
7.8 KHz
T8-7.0 1228
1228 F26.0
ECOMn CAPPn CAPNn
MATn
TOGn
PWMn ECCFn
CCAPMn
n=0 to 4
CL
CCAPnL
CCAPnH
PCA Timer/Counter
0
00
8-bit Comparator
Overflow
CL < CCAPnL
CL >= CCAPnL
Enable
CEXn
0
1
相关PDF资料
PDF描述
SST89E554A-40-I-TQJ 8-BIT, FLASH, 40 MHz, MICROCONTROLLER, PQFP44
SSTE32882HLBAKG SSTE SERIES, PLL BASED CLOCK DRIVER, 4 TRUE OUTPUT(S), 0 INVERTED OUTPUT(S), PBGA176
SSTE32882HLBBKG SSTE SERIES, PLL BASED CLOCK DRIVER, 4 TRUE OUTPUT(S), 0 INVERTED OUTPUT(S), PBGA176
SSTUA32864EC,557 SSTU SERIES, POSITIVE EDGE TRIGGERED D FLIP-FLOP, TRUE OUTPUT, PBGA96
SSTUA32866EC/G 32866 SERIES, POSITIVE EDGE TRIGGERED D FLIP-FLOP, COMPLEMENTARY OUTPUT, PBGA96
相关代理商/技术参数
参数描述
SST89E554RC 制造商:SST 制造商全称:Silicon Storage Technology, Inc 功能描述:FlashFlex51 MCU
SST89E554RC-25-C-NI 制造商:SST 制造商全称:Silicon Storage Technology, Inc 功能描述:FlashFlex51 MCU
SST89E554RC-25-C-NJ 制造商:SST 制造商全称:Silicon Storage Technology, Inc 功能描述:FlashFlex51 MCU
SST89E554RC-25-C-PI 制造商:SST 制造商全称:Silicon Storage Technology, Inc 功能描述:FlashFlex51 MCU
SST89E554RC-25-C-PJ 制造商:SST 制造商全称:Silicon Storage Technology, Inc 功能描述:FlashFlex51 MCU