AT87C52X2-SLSUM Atmel, AT87C52X2-SLSUM Datasheet - Page 9
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AT87C52X2-SLSUM
Manufacturer Part Number
AT87C52X2-SLSUM
Description
IC 8051 MCU 8K OTP 40MHZ 44PLCC
Manufacturer
Atmel
Series
87Cr
Datasheet
1.TS87C52X2-VCA.pdf
(55 pages)
Specifications of AT87C52X2-SLSUM
Core Processor
8051
Core Size
8-Bit
Speed
40/20MHz
Connectivity
UART/USART
Peripherals
POR
Number Of I /o
32
Program Memory Size
8KB (8K x 8)
Program Memory Type
OTP
Ram Size
256 x 8
Voltage - Supply (vcc/vdd)
4.5 V ~ 5.5 V
Oscillator Type
Internal
Operating Temperature
-40°C ~ 85°C
Package / Case
44-PLCC
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Eeprom Size
-
Data Converters
-
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Figure 2. Mode Switching Waveforms
4184G–8051–09/06
XTAL1
XTAL1:2
X2 bit
CPU clock
STD Mode
The X2 bit in the CKCON register (See Table 3.) allows to switch from 12 clock cycles
per instruction to 6 clock cycles and vice versa. At reset, the standard speed is activated
(STD mode). Setting this bit activates the X2 feature (X2 mode).
Note:
Table 3. CKCON Register
CKCON - Clock Control Register (8Fh)
Reset Value = XXXX XXX0b
Not bit addressable
For further details on the X2 feature, please refer to ANM072 available on the web
(http://www.atmel.com)
Number
Bit
7
-
7
6
5
4
3
2
1
0
In order to prevent any incorrect operation while operating in X2 mode, user must be
aware that all peripherals using clock frequency as time reference (UART, timers) will
have their time reference divided by two. For example a free running timer generating an
interrupt every 20 ms will then generate an interrupt every 10 ms. UART with 4800 baud
rate will have 9600 baud rate.
Mnemonic Description
Bit
X2
6
-
-
-
-
-
-
-
-
Reserved
The value read from this bit is indeterminate. Do not set this bit.
Reserved
The value read from this bit is indeterminate. Do not set this bit.
Reserved
The value read from this bit is indeterminate. Do not set this bit.
Reserved
The value read from this bit is indeterminate. Do not set this bit.
Reserved
The value read from this bit is indeterminate. Do not set this bit.
Reserved
The value read from this bit is indeterminate. Do not set this bit.
Reserved
The value read from this bit is indeterminate. Do not set this bit.
CPU and peripheral clock bit
Clear to select 12 clock periods per machine cycle (STD mode, F
Set to select 6 clock periods per machine cycle (X2 mode, F
X2 Mode
5
-
4
-
3
-
2
-
STD Mode
TS8xCx2X2
1
OSC
-
=F
OSC
XTAL
=F
).
XTAL
X2
0
/
2).
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