参数资料
型号: MC68HC05RC18DW
厂商: MOTOROLA INC
元件分类: 微控制器/微处理器
英文描述: 8-BIT, MROM, 2.1 MHz, MICROCONTROLLER, PDSO28
封装: SOIC-28
文件页数: 96/124页
文件大小: 457K
代理商: MC68HC05RC18DW
Carrier Modulator Transmitter (CMT)
Carrier Generator
MC68HC05RC18 Rev. 2.0
General Release Specification
MOTOROLA
Carrier Modulator Transmitter (CMT)
73
NON-DISCLOSURE
AGREEMENT
REQUIRED
9.4.1 Time Counter
The high/low time counter is a 6-bit up counter. After each increment, the
contents of the counter are compared with the appropriate high or low
count value register. When this value is reached, the counter is reset and
the compare is redirected to the other count value register. Assuming
that the high time count compare register is currently active, a valid
compare will cause the carrier output to be driven low. The counter will
continue to increment and when reaching the value stored in the
selected low count value register, it will be cleared and will cause the
carrier output to be driven high. The cycle repeats, automatically
generating a periodic signal which is directed to the modulator. The
lowest frequency (maximum period) and highest frequency (minimum
period) which can be generated are defined as:
fmax = fosc ÷ (2 x 1) Hz
fmin = fosc ÷ (2 x (2
6 – 1)) Hz
In the general case, the carrier generator output frequency is:
fout = fosc ÷ (Highcount + Lowcount) Hz
Where:
0 <
Highcount < 64 and
0 <
Lowcount < 64
NOTE:
These equations assume the DIV2 bit (bit 6) of the MCSR is clear. When
the DIV2 bit is set, the carrier generator frequency will be half of what is
shown in these equations.
The duty cycle of the carrier signal is controlled by varying the ratio of
high time to low + high time. As the input clock period is fixed, the duty
cycle resolution will be proportional to the number of counts required to
generate the desired carrier period.
Duty Cycle
Highcount
Lowcount
+
----------------------------------------------------------------
=
相关PDF资料
PDF描述
MC68HC05SR3B 8-BIT, MROM, 2 MHz, MICROCONTROLLER, PDIP42
MC68HC705SR3CP 8-BIT, OTPROM, 2 MHz, MICROCONTROLLER, PDIP40
MC68HC705SR3CFB 8-BIT, OTPROM, 2 MHz, MICROCONTROLLER, PQFP44
MC68HC705SR3CB 8-BIT, OTPROM, 2 MHz, MICROCONTROLLER, PDIP42
MC68HC05SR3CB 8-BIT, MROM, 2 MHz, MICROCONTROLLER, PDIP42
相关代理商/技术参数
参数描述
MC68HC05RC8 制造商:FREESCALE 制造商全称:Freescale Semiconductor, Inc 功能描述:General Release Specification
MC68HC05RC8DW 制造商:FREESCALE 制造商全称:Freescale Semiconductor, Inc 功能描述:General Release Specification
MC68HC05RC8FN 制造商:FREESCALE 制造商全称:Freescale Semiconductor, Inc 功能描述:General Release Specification
MC68HC05RC8P 制造商:FREESCALE 制造商全称:Freescale Semiconductor, Inc 功能描述:General Release Specification
MC68HC05SC24 制造商:MOTOROLA 制造商全称:Motorola, Inc 功能描述:Secure 8-bit microcomputer with EEPROM