PXD10RM Datasheet, PDF (170/1332 Pages) Freescale Semiconductor, Inc – PXD10 Microcontroller

6.5.5 Boot from UART
6.5.5.1 Configuration
Boot from UART protocol is implemented by the LINFlex 0 module. The pins used are:
• LINFlex_TX corresponds to pin PB[2]
• LINFlex_RX corresponds to pin PB[3].
The system clock is driven by an external oscillator.
The LINFlex controller is configured to operate at a baud rate = system clock frequency/833 (see Table 6-6
for baud rate example), using an 8-bit data frame without parity bit and 1 stop bit.
Figure 6-7. LINFlex Bit Timing in UART Mode
6.5.5.2 Protocol
Table 6-7 summarizes the protocol and BAM action during this boot mode.
Table 6-7. UART Boot Mode Download Protocol (Autobaud Disabled)
Protoc
ol step
Host sent
message
BAM response
message
Action
1
64-bit password
64-bit password Password checked for validity and compared against stored
(MSB first)
password.
2
32-bit store address 32-bit store address
Load address is stored for future use.
3
VLE bit +
VLE bit +
31-bit number of 31-bit number of
bytes (MSB first) bytes (MSB first)
Size of download is stored for future use.
Verify if VLE bit is set to 1
4
8 bits of raw
binarydata
8 bits of raw binary
data
8-bit data are packed into 32-bit words. This word is saved in
SRAM starting from the “Load address”.
“Load address” increments until the number of data received
and stored matches the size as specified in the previous step.
5
none
none
Branch to dowloaded code
6-12
PXD10 Microcontroller Reference Manual, Rev. 1
Preliminary—Subject to Change Without Notice
Freescale Semiconductor