ST7FOXK1 STMicroelectronics, ST7FOXK1 Datasheet - Page 34

• Manufacturer Part Number: ST7FOXK1
• Description: Low cost flash 8bit micro
• Manufacturer: STMicroelectronics

Specifications of ST7FOXK1

• 4 To 8 Kbytes Single Voltage Extended Flash (xflash) Program Memory With Read-out Protection In-circuit Programming And In-application Programming (icp And Iap) Endurance: 1K write/erase cycles guaranteed Data retention
• Clock Sources: Internal trimmable 8 MHz RC oscillator, auto wakeup internal low power - low frequency oscillator, crystal/ceramic resonator or external clock
• Five Power Saving Modes: Halt, Active-Halt, Auto Wakeup from Halt, Wait and Slow
• A/d Converter: up to 10 input channels

Supply, reset and clock management
6
6.1
6.1.1
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Supply, reset and clock management
The device includes a range of utility features for securing the application in critical
situations (for example in case of a power brown-out), and reducing the number of external
components. The main features are the following:
RC oscillator adjustment
Internal RC oscillator
The device contains an internal RC oscillator with a specific accuracy for a given device,
temperature and voltage range (4.5 V - 5.5 V). It must be calibrated to obtain the frequency
required in the application. This is done by software writing a 10-bit calibration value in the
RCCRH (RC Control register High) and in the bits 6:5 in the RCCRL (RC Control register
Low).
Whenever the microcontroller is reset, the RCCR returns to its default value (FFh), i.e. each
time the device is reset, the calibration value must be loaded in the RCCR. Predefined
calibration values are stored for 5 V V
Table 7.
1. The DEE0h and DEE1h addresses are located in a reserved area in non-volatile memory. They are read-
In 38-pulse ICC mode, the internal RC oscillator is forced as a clock source, regardless of
the selection in the option byte.
Section 12: Electrical characteristics on page 187
and accuracy of the RC oscillator.
To improve clock stability and frequency accuracy, it is recommended to place a decoupling
capacitor, typically 100 nF, between the V
V
SSA
only bytes for the application code. This area cannot be erased or programmed by any ICC operations.
For compatibility reasons with the RCCRL register, CR[1:0] bits are stored in the 5th and 6th position of
DEE1 address.
Clock management
–
–
–
–
Reset Sequence Manager (RSM)
System Integrity management (SI)
–
RCCRH
RCCRL
pins as close as possible to the ST7 device.
RCCR
8 MHz internal RC oscillator (enabled by option byte)
Auto wakeup RC oscillator (enabled by option byte)
1 to 16 MHz or 32 kHz External crystal/ceramic resonator (selected by option byte)
External clock input (enabled by option byte)
Main supply Low voltage detection (LVD) with reset generation (enabled by option
byte)
Predefined RC oscillator calibration values
f
Conditions
RC
T
V
A
DD
= 25°C
= 8 MHz
= 5V
DD
supply voltage at 25 °C (see
DD
and V
for more information on the frequency
SS
pins and also between the V
ST7FOXF1, ST7FOXK1, ST7FOXK2
DEE0h
DEE1h
Address
ST7FOX
(1)
(1)
(CR[9:2])
(CR[1:0])
Table
7).
DDA
and