Maxim Integrated MAX31782 - Manual (Page 164)

MaximIntegrated 18-13
MAX31782 User’s Guide
Revision 0; 8/11
18.3.16Command30h—CRCCode
This command returns the CRC-16 value (CRCH:CRCL) of the (LengthH:LengthL) bytes of program flash starting at
(AddrH:AddrL) . The formula for the CRC calculation is X
16 + X 15 + X 2 + 1 . This command is password protected .
The CRC calculation takes approximately 45 system clock cycles per byte . During this time polling should be performed
to determine when the loader has finished executing the CRC calculation . If using the I
2 C loader, use the polling method
shown in Figure 18-2 . When a data string is read that has B7, CRCL, CRCH, 3Eh, the host knows that the calculation
completed successfully . If using the JTAG loader, the JTAG status bits can be used to determine when the CRC cal-
culation is complete .
18.3.17Command31h—CRCData
This command returns the CRC-16 value (CRCH:CRCL) of the (LengthH:LengthL) bytes of data memory starting at
(AddrH:AddrL) . The formula for the CRC calculation is X
16 + X 15 + X 2 + 1 . This command is password protected .
The CRC calculation takes approximately 45 system clock cycles per byte . During this time polling should be performed
to determine when the loader has finished executing the CRC calculation . If using the I
2 C loader, use the polling method
shown in Figure 18-2 . When a data string is read that has B7, CRCL, CRCH, 3Eh, the host knows that the calculation
completed successfully . If using the JTAG loader, the JTAG status bits can be used to determine when the CRC cal-
culation is complete .
18.3.18Command40h—VerifyCode
This command operates in the same manner as the Load Code command, except that instead of programming the
input data into flash memory, it verifies that the input data matches the data already in code space . If the data does not
match, the status code is set to reflect this failure . This command is password protected .
18.3.19Command41h—VerifyData
This command operates in the same manner as the Load Data command, except that instead of writing the input data
into SRAM, it verifies that the input data matches the data already in data space . If the data does not match, the status
code is set to reflect this failure . This command is password protected .
Byte1 Byte2 Byte3 Byte4 Byte5 Byte6 Byte7 Byte8 Byte9 Byte10 Byte11
Command
Data
In Data
In Data
In
DataIn DataIn NOP
Data
Out Data
Out
Return
Dummy
RX
Input 30h 2 AddrL AddrH LengthL LengthH 00h 00h 00h 00h 00h
Output X X X X X X X CRCL CRCH 3Eh X
Byte1 Byte2 Byte3 Byte4 Byte5 Byte6 Byte7 Byte8 Byte9 Byte10 Byte11
Command
Data
In Data
In Data
In
DataIn DataIn NOP
Data
Out Data
Out
Return
Dummy
RX
Input 31h 2 AddrL AddrH LengthL LengthH 00h 00h 00h 00h 00h
Output X X X X X X X CRCL CRCH 3Eh X
Byte1 Byte2 Byte3 Byte4 (Length)Bytes
Byte
Length+5 Byte
Length+6 Byte
Length+7
Command DataIn DataIn DataIn DataIn NOP Return DummyRX
Input 40h Length AddrL AddrH Data to Verify 00h 00h 00h
Output X X X X X X 3Eh X
Byte1 Byte2 Byte3 Byte4 (Length)Bytes
Byte
Length+5 Byte
Length+6 Byte
Length+7
Command DataIn DataIn DataIn DataIn NOP Return DummyRX
Input 41h Length AddrL AddrH Data to Verify 00h 00h 00h
Output X X X X X X 3Eh X