ST10F276Z5 STMicroelectronics, ST10F276Z5 Datasheet - Page 57

• Manufacturer Part Number: ST10F276Z5
• Description: 16-BIT MICROCONTROLLER WITH MAC UNIT, UP TO 832 KBYTES FLASH MEMORY AND UP TO 68 KBYTES RAM
• Manufacturer: STMicroelectronics

Specifications of ST10F276Z5

• Single Voltage Supply: 5V ±10% (embedded regulator for 1.8 V core supply)

ST10F276Z5
5.3.5
Note:
This process may go through several iterations or may directly execute the final application.
In all cases the device still runs in BSL mode, that is, with the watchdog timer disabled and
limited access to the internal Flash area. All code fetches from the internal IFLASH area
(01’0000
access the internal Flash of the device.
Choosing the baud rate for the BSL via UART
The calculation of the serial baud rate for ASC0 from the length of the first zero byte that is
received allows the operation of the bootstrap loader of the device with a wide range of baud
rates. However, the upper and lower limits must be kept to ensure proper data transfer.
The device uses timer T6 to measure the length of the initial zero byte. The quantization
uncertainty of this measurement implies the first deviation from the real baud rate; the next
deviation is implied by the computation of the S0BRL reload value from the timer contents.
The formula below shows the association:
For a correct data transfer from the host to the device, the maximum deviation between the
internal initialized baud rate for ASC0 and the real baud rate of the host should be below
2.5%. The deviation (F
calculated using the formula below:
Function (F
the serial communication.
This baud rate deviation is a nonlinear function depending on the CPU clock and the baud
rate of the host. The maxima of the function (F
the smaller baud rate prescaler factors and the implied higher quantization error (see
Figure
Figure 10. Baud rate deviation between host and ST10F276Z5
The minimum baud rate (B
of timer T6, when measuring the zero byte, that is, it depends on the CPU clock. Using the
maximum T6 count 2
2.5%
10).
H
B
F
...08’FFFF
Low
B
B
) does not consider the tolerances of oscillators and other devices supporting
H
16
) are redirected to the special Test-Flash. Data read operations
B
F B
in the formula the minimum baud rate is calculated. The lowest
, in percent) between host baud rate and device baud rate can be
=
S0BRL
B
Low
High
B Contr B Host
------------------------------------------- 100
B
in
ST10F276
B Contr
Figure
=
–
T6 36
------------------- -
I
72
–
=
10) is determined by the maximum count capacity
II
--------------------------------------------- -
32
⋅
,
B
) increases with the host baud rate due to
T6
⋅
(
S0BRL
f CPU
%
=
,
9
-- -
4
⋅
---------------- -
B Host
f CPU
+
F B
1
)
≤
2.5
%
Bootstrap loader
B
HOST
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