ST10F269-T3 STMicroelectronics, ST10F269-T3 Datasheet - Page 30

• Manufacturer Part Number: ST10F269-T3
• Manufacturer: STMicroelectronics

Specifications of ST10F269-T3

• Cpu Family: ST10
• Device Core Size: 16b
• Frequency (max): 32MHz
• Interface Type: ASC/I2C/SSC
• Program Memory Type: Flash
• Program Memory Size: 256KB
• Total Internal Ram Size: 12KB
• # I/os (max): 111
• Number Of Timers - General Purpose: 4
• Operating Supply Voltage (typ): 5V
• Operating Supply Voltage (max): 5.5V
• Operating Supply Voltage (min): 4.5V
• On-chip Adc: 16-chx10-bit
• Instruction Set Architecture: CISC/RISC
• Operating Temp Range: -40C to 125C
• Operating Temperature Classification: Automotive
• Mounting: Surface Mount
• Pin Count: 144
• Package Type: TQFP
• Lead Free Status / Rohs Status: Supplier Unconfirmed

ST10F269-T3
5.6 - Bootstrap Loader
The built-in bootstrap loader (BSL) of the
ST10F269-T3 provides a mechanism to load the
startup program through the serial interface after
reset. In this case, no external memory or internal
Flash memory is required for the initialization
code starting at location 00’0000h (see Figure 5).
The bootstrap loader moves code/data into the
internal RAM, but can also transfer data via the
serial interface into an external RAM using a
second level loader routine. Flash Memory
(internal or external) is not necessary, but it may
be used to provide lookup tables or “core-code”
like a set of general purpose subroutines for I/O
operations,
initialization, etc.
The bootstrap loader can be used to load the
complete application software into ROMless
systems,
complete systems for testing or calibration, or to
load a programming routine for Flash devices.
The BSL mechanism can be used for standard
system startup as well as for special occasions
like system maintenance (firmer update) or
end-of-line programming or testing.
Figure 5 : Bootstrap Loader Sequence
30/162
CSP:IP
RSTIN
1) BSL initialization time
2) Zero Byte (1 start bit, eight ‘0’ data bits, 1 stop bit), sent by host.
3) Identification Byte (D5h), sent by ST10F269-T3.
4) 32 Bytes of code / data, sent by host.
5) Caution: TxD0 is only driven a certain time after reception of the zero Byte.
6) Internal Boot ROM.
P0L.4
RxD0
TxD0
to
number
load
temporary
crunching,
1)
6)
2)
software
Internal Boot Memory (BSL) routine
5)
system
into
3)
5.6.1 - Entering the Bootstrap Loader
The ST10F269-T3 enters BSL mode when pin
P0L.4 is sampled low at the end of a hardware
reset. In this case the built-in bootstrap loader is
activated independent of the selected bus mode.
The bootstrap loader code is stored in a special
Boot-ROM. No part of the standard mask Memory
or Flash Memory area is required for this.
After entering BSL mode and the respective
initialization the ST10F269-T3 scans the RXD0
line to receive a zero Byte, one start bit, eight ‘0’
data bits and one stop bit.
From the duration of this zero Byte it calculates
the corresponding Baud rate factor with respect to
the current CPU clock, initializes the serial
interface ASC0 accordingly and switches pin
TxD0 to output.
Using this Baud rate, an identification Byte is
returned to the host that provides the loaded data.
This identification Byte identifies the device to
be booted. The identification byte is D5h for
ST10F269-T3.
4)
32 Byte user software