
DS4830A User’s Guide
188
22.3.14 – Command 21h – Dump Data
This command returns the contents of the SRAM memory. The memory dump begins at byte address AddrH:AddrL
and will contain LengthH:LengthL bytes. This command is password protected.
22.3.15 – Command 30h – CRC Code
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 (4.5µs/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, user should wait for time according to given length and read CRCL, CRCH, 3Eh. If using the JTAG loader,
the JTAG status bits can be used to determine when the CRC calculation is complete.
22.3.16 – Command 31h – CRC Data
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 (4.5µs/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, user should wait for time according to given length and read CRCL, CRCH, 3Eh. If using the JTAG loader,
the JTAG status bits can be used to determine when the CRC calculation is complete.
Commentaires sur ces manuels