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参数资料
型号： 7548
厂商： Renesas Technology Corp.
英文描述： SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER
中文描述： 单芯片8位CMOS微机
文件页数： 43/73页
文件大小： 1255K
代理商： 7548
Rev.2.00
REJ03B0210-0200
Mar 15, 2007
Page 43 of 70
7548 Group
PRELIMINARY
Notice: This is not a final specification.
Some parametric limits are subject to change.
Clock Circuit
The clock circuit includes the X
IN
clock (ceramic oscillator or
crystal oscillator can be used), X
CIN
clock (32 kHz oscillator can
be used), external clock input, high-speed on-chip oscillator, and
low-speed on-chip oscillator.
Pins P2
0
/X
OUT
/X
COUT
and P2
1
/X
IN
/X
CIN
can be shared for the
ports, X
IN
oscillation, and X
CIN
oscillation.
Use the oscillation method selection bits (bits 1 and bit 0 in
function set ROM data 1 (FSROM1)) to set the function of these
pins.
Ceramic Resonator or Crystal Oscillator
Set the oscillation method selection bits (bits 1 and bit 0 in
FSROM1) to “01
2
”, and connect the resonator (or the oscillator)
and external circuit with the shortest wiring length possible.
The constants of the oscillator circuit differ depending on the
resonator. Use the values recommended by the resonator
manufacturer. (An external feedback resistor may be necessary
under some conditions.)
Setting the X
IN
/X
CIN
oscillation control bit to “0” starts
oscillation. This bit is sets to “0” after reset.
32 kHz Crystal Oscillator
Set the oscillation method selection bits to “10
2
”, and connect the
32 kHz crystal oscillator and external circuit with the shortest
wiring length possible.
The constants of the oscillator circuit differ depending on the
resonator. Use the values recommended by the resonator
manufacturer. (An external feedback resistor may be necessary
under some conditions.)
Setting the X
IN
/X
CIN
oscillation control bit to “0” starts
oscillation. This bit is sets to “0” after reset.
External Clock Input
Set the oscillation method selection bits to “11
2
”, and connect the
clock source to the P2
0
/X
OUT
pin. In this case, the P2
1
/X
IN
pin
can be used as an I/O port.
High-Speed On-Chip Oscillator
The high-speed on-chip oscillator is stopped after reset.
Setting the high-speed on-chip oscillator oscillation control bit
(bit 1 in CLKM) to “0” starts oscillation. This bit is sets to “1”
after reset.
Low-Speed On-Chip Oscillator
The low-speed on-chip oscillator automatically starts oscillating
after reset.
Setting the low-speed on-chip oscillator oscillation control bit
(bit 0 in CLKM) to “1” stops oscillation. This bit is sets to “0”
after reset. If the low-speed on-chip oscillator control bit (bit 4 in
FSROM2) is set to “0” and stopping the low-speed on-chip
oscillator is disabled, the low-speed on-chip oscillator oscillation
control bit cannot be set to “1” and oscillation cannot be stopped.
Also, the oscillator does not stop even when the STP instruction
is executed.
Using No Oscillator Pins (P2
0
as output port and P2
1
as I/O port)
To use only an internal on-chip oscillator, set the oscillation
method selection bits to “00
2
”. The P2
0
/X
OUT
pin can be used as
an output port and the P2
1
/X
IN
pin can be used as an I/O port.
Fig 58. Structure of function set ROM data 1
Fig 59. External circuit of ceramic resonator
Fig 60. External circuit of 32 kHz quarts-crystal
oscillator
Fig 61. External clock input circuit
Oscillation method selection bits (Note 1)
b1 b0
0 0: Clock pins not used (P2
0
/X
OUT
and P2
1
/X
IN
are used as
I/O ports)
0 1: Ceramic resonator or quarts-crystal oscillator
1 0: 32 kHz quarts-crystal oscillator
1 1: External clock input (P2
1
/X
IN
pin is used as I/O port)
Low voltage detection circuit valid bit in the stop mode (Note 2)
0: Low voltage detection circuit invalid in the stop mode
1: Low voltage detection circuit valid in the stop mode
Set “0” to these bits certainly.
Set “1” to this bit certainly.
b7
Function set ROM data 1
FSROM1 (FFD9
16
)
b0
Notes1:
The P2
0
/X
OUT
and P2
1
/X
IN
pins build in an on-chip oscillator. Even if these pins are used
as I/O ports, the oscillator circuit is enabled when the MCU’s Vcc voltage drops below
the operation limit voltage. In this case these pins may output undefined values.
2:
When the Low voltage detection circuit is set to be valid in the stop mode, the dissipation
current in the stop mode is increased.
M37548
X
IN
X
OUT
Rd
C
OUT
C
IN
Insert a damping resistor if required.
The resistance will vary depending
on the oscillator and the oscillation
drive capacity setting.
Use the value recommended by the
maker of the oscillator.
Also, if the oscillator manufacturer’s
data sheet specifies that a feedback
resistor be added external to the chip
though a feedback resistor exists on-
chip, insert a feedback resistor
between X
IN
and X
OUT
following the
instruction.
M37548
X
CIN
X
COUT
Rd
C
OUT
C
IN
Insert a damping resistor if required.
The resistance will vary depending
on the oscillator and the oscillation
drive capacity setting.
Use the value recommended by the
maker of the oscillator.
Also, if the oscillator manufacturer’s
data sheet specifies that a feedback
resistor be added external to the
chip though a feedback resistor
exists on-chip, insert a feedback
resistor between X
IN
and X
OUT
following the instruction.
M37548
P2
1
X
OUT
I/O port
External
oscillation circuit
Vcc
Vss
Connect the external clock
to the P2
0
/X
OUT
pin, not
the P2
1
/X
IN
pin.
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相关代理商/技术参数
参数描述
7548_07 制造商:RENESAS 制造商全称:Renesas Technology Corp 功能描述:Standard Characteristics
7548_0710 制造商:RENESAS 制造商全称:Renesas Technology Corp 功能描述:SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER
75481-001 功能描述:集管和线壳 BACKPANEL PINS RoHS:否 产品种类:1.0MM Rectangular Connectors 产品类型:Headers - Pin Strip 系列:DF50 触点类型:Pin (Male) 节距:1 mm 位置/触点数量:16 排数:1 安装风格:SMD/SMT 安装角:Right 端接类型:Solder 外壳材料:Liquid Crystal Polymer (LCP) 触点材料:Brass 触点电镀:Gold 制造商:Hirose Connector
75481-002 功能描述:集管和线壳 BERGPIN - WITH LARGE STA-R RoHS:否 产品种类:1.0MM Rectangular Connectors 产品类型:Headers - Pin Strip 系列:DF50 触点类型:Pin (Male) 节距:1 mm 位置/触点数量:16 排数:1 安装风格:SMD/SMT 安装角:Right 端接类型:Solder 外壳材料:Liquid Crystal Polymer (LCP) 触点材料:Brass 触点电镀:Gold 制造商:Hirose Connector
75481-004 功能描述:集管和线壳 BERGPIN RoHS:否 产品种类:1.0MM Rectangular Connectors 产品类型:Headers - Pin Strip 系列:DF50 触点类型:Pin (Male) 节距:1 mm 位置/触点数量:16 排数:1 安装风格:SMD/SMT 安装角:Right 端接类型:Solder 外壳材料:Liquid Crystal Polymer (LCP) 触点材料:Brass 触点电镀:Gold 制造商:Hirose Connector
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