MPC563XM Reference Manual, Rev. 1
Freescale Semiconductor
617
Preliminary—Subject to Change Without Notice
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Messages with 0x13 ID are used to send the downloaded data. The device transmits back received
data with message ID of 0x3.
When the SCI is used for serial download, the data has to be sent on a byte-by-byte basis. the device
transmits back the received data.
21.5.5.4
Download Protocol Execution
The BAM program executes the serial boot as following:
1. Download 64-bit password.
The received 8-byte password is checked for validity. For a password to be valid, none of its four
16-bit half words must equal 0x0000 or 0xFFFF.
The BAM program then checks the censorship status of the device by checking the DISNEX bit in
the SIU_CCR register. If Nexus is disabled, the device is considered to be censored and the
password is compared with a password stored in the shadow row in internal flash memory.
If Nexus is enabled, the device is not considered to be censored and the password is compared to
the fixed value = 0xFEED_FACE_CAFE_BEEF.
If the password check fails, the device stops responding. To get the device out of that state, the
RESET signal must be asserted.
If the password check passes, the BAM transitions to the next step in the protocol.
2. Download start address, size of download, and VLE bit.
The next 8 bytes received by the device are considered to contain a 32-bit start address, the VLE
mode bit, and a 31-bit code length (see
Figure 21-7. Start Address, VLE Bit and Download Size in Bytes
The start address defines where the received data will be stored and where the device will branch
after the download is finished. The two least significant bits of the start address are ignored by the
BAM program, such that the loaded code should be 32-bit word aligned.
The length defines how many data bytes to be loaded.
The VLE mode bit instructs the device to program MMU entries 1-3 with VLE attribute. If it is 1,
the downloaded code must be compiled to VLE instructions, if it is 0 the code contains classic
Power Book E architecture instructions.
3. Download data.
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
START_ADDRESS[0:15]
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
START_ADDRESS[16:31]
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
VLE
CODE_LENGTH[0:14]
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
CODE_LENGTH[15:30]