Firmware User Manual (AE-step)
51
Revision 1.02
2019-04-24
TLE984x Firmware User Manual
4.4.6
Command 87
H
– NVM: Read Data
Firmware supports reading of data and code from the device’s internal NVM via command 87
H
.
The host initiates the NVM read by sending a header block message. This message contains information about
the NVM location (offset address based on NVM start address) and the number of read data bytes.
BootROM sends back the requested data by Data Block message and by a terminating EOT block message. The
Data Block messages are used if the amount of read data exceeds the Data field size of the EOT block message.
NVM pages can only be read if there is no NVM HW read protection applied to any NVM region. Details about
the NVM access protection are given in
Command 89H – NVM: Protection Set / Clear
. If reading from an
address, which belongs to the non-linear NVM region and the page is not mapped (previous programmed), the
read is rejected.
This message supports reading of a maximum of 128 bytes from the NVM. Larger memory blocks need to be
split into multiple
Command 87
H
– NVM: Read Data
messages.
The host waiting time before response is sent back/can be asked for:
• 8 ms
Header Block
Table 4-19 “Command 87
H
– NVM: Read Data” Header Block Field Description
Field
Description
Length
Number of following bytes in the header block. Always set to 06
H
Message Type
NVM read data command. Always set to 87
H
Address Byte #0(MSB) 24-bit NVM address offset where to read the data.
The offset starts counting from the NVM start address 1100.0000
H
Address Byte #1
Address Byte #2(LSB)
Number
8-bit number of data bytes to read. The BootROM will send these bytes in Data Blocks
and an EOT block.
Maximum supported length: 128 bytes.
BSL20_MODE05_HEADER
.
0
1
2
3
4
5
Length
Message
Type
Reserved
Number
6
Address
Byte #0
(MSB)
Address
Byte #1
Address
Byte #2
(LSB)
