参数资料
型号: SPMC16V1CPU20
厂商: MOTOROLA INC
元件分类: 微控制器/微处理器
英文描述: 16-BIT, MROM, 20.97 MHz, MICROCONTROLLER, PQFP100
封装: TQFP-100
文件页数: 46/128页
文件大小: 571K
代理商: SPMC16V1CPU20
MOTOROLA
MC68HC16V1
24
MC68HC16V1TS/D
3.3.4 Clock Control
The clock control circuits determine system clock frequency and clock operation under special circum-
stances, such as following loss of synthesizer reference or during low-power operation. Clock source is
determined by the logic state of the two shadow bits in the port/clock configuration register (PCON2 and
PCON0) and VDDSYN pin during reset.
The synthesizer control register (SYNCR) can be read or written at any time. The encoding and default
value of the upper byte of SYNCR depend on the clock mode selected at reset.
For slow reference mode, the default value is $3F, which corresponds to an operating frequency of 256
times fref. For a 32.768 kHz crystal, the operating frequency is 8.388 MHz.
In fast reference mode, with PCON2 cleared to zero, the default value of the upper byte is $80, which
corresponds to a 1-to-1 match of the reference frequency. With PCON2 set to one, the default value of
the upper byte is $30, which corresponds to an operating frequency of two times fref. For a 4.194 MHz
crystal, the operating frequency is 8.388 MHz.
In external clock mode, the default value of the upper byte is $80, which corresponds to an operating
frequency which is equal to the input frequency on EXTAL. Strict minimum duty cycle requirements ap-
ply. Refer to 3.3.2 Clock Modes for more information. The default value is forced into the SYNCR upon
reset, along with the default values of the other bits in the register.
X — Frequency Control Bit
This bit controls a one-bit divider which drives the system clock in all modes. When X is set, the divider
is bypassed; when clear, the system clock is divided by two.
SYNCR — Synthesizer Control Register
$YFFA04
Slow Reference Mode
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
X
W
Y[5:0]
EDIV
STOSC LOSCD
SLIMP
SLOCK RSTEN
STSLIM
STEXT
RESET:
0
1
0
1
0
Fast Reference Mode
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
X
W[2:0]
RSVD
Y[2:0]
EDIV
STOSC LOSCD
SLIMP
SLOCK RSTEN
STSLIM
STEXT
RESET:
PCON2
0
PCON2 PCON2
0
1
0
External Clock Mode
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
X
RSVD
Y[2:0]
EDIV
STOSC LOSCD
SLIMP
SLOCK RSTEN
STSLIM
STEXT
RESET:
1
0
1
0
1
0
相关PDF资料
PDF描述
S1C60N05F0A0100 MICROCONTROLLER, PQFP60
SC3S12P128J0CLHR 16-BIT, MROM, 1.05 MHz, MICROCONTROLLER, PQFP64
SC3S12P128J0CLH 16-BIT, MROM, 1.05 MHz, MICROCONTROLLER, PQFP64
SC3S12P128J0CQKR 16-BIT, MROM, 1.05 MHz, MICROCONTROLLER, PQFP80
S908QY2AD1MDW 8-BIT, FLASH, 8 MHz, MICROCONTROLLER, PDSO16
相关代理商/技术参数
参数描述
SPMC387-01 制造商:SSDI 制造商全称:Solid States Devices, Inc 功能描述:50 WATT RADIATION HARDENED DC-DC POWER CONVERTER
SPMC68CK338CPV14 制造商:FREESCALE 制造商全称:Freescale Semiconductor, Inc 功能描述:32-Bit Modular Microcontroller
SPMC802B 制造商:未知厂家 制造商全称:未知厂家 功能描述:32-pin General Purpose Microcontroller (OTP)
SPMC802B-C 制造商:未知厂家 制造商全称:未知厂家 功能描述:32-pin General Purpose Microcontroller (OTP)
SPMC802B-PD03 制造商:未知厂家 制造商全称:未知厂家 功能描述:32-pin General Purpose Microcontroller (OTP)