NXP Semiconductors MPC5606S - Boot from UART

Boot Assist Module (BAM)
MPC5606S Microcontroller Reference Manual, Rev. 7
176 Freescale Semiconductor
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)
Protocol
step
Host sent
message
BAM response
message
Action
1 64-bit password
(MSB first)
64-bit password Password checked for validity and compared against stored
password.
2 32-bit store address 32-bit store address Load address is stored for future use.
3 VLE bit +
31-bit number of
bytes (MSB first)
VLE bit +
31-bit number of
bytes (MSB first)
Size of download is stored for future use.
Verify if VLE bit is set to 1.
4 8 bits of raw binary
data
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 amount of data received
and stored matches the size as specified in the previous step.
5 None None Branch to downloaded code.