Maxim Integrated 71M6541 Demo Board - Manual (Page 20)

71M6541 Demo Board REV 3.0 User’s Manual
20 Rev 4.0
1.9.4 UPDATING CALIBRATION DATA IN FLASH OR EEPROM
It is possible to make data permanent that had been entered temporarily into the CE RAM. The transfer to
EEPROM memory is done using the following serial interface command:
>]CLS
Thus, after transferring calibration data with manual serial interface commands or with a macro file, all that has
to be done is invoking the U command.
Similarly, calibration data can be restored to default values using the CLD command.
After reset, calibration data is copied from the EEPROM, if present. Otherwise, calibration
data is copied from the flash memory. Writing 0xFF into the first few bytes of the EEPROM
deactivates any calibration data previously stored to the EEPROM.
1.9.5 LOADING THE CODE FOR THE 71M6541 INTO THE DEMO BOARD
Hardware Interface for Programming: The 71M6541F IC provides an interface for loading code into the inter-
nal flash memory. This interface consists of the following signals:
E_RXTX (data), E_TCLK (clock), E_RST (reset), ICE_E (ICE enable)
These signals, along with V3P3D and GND are available on the emulator headers J14.
Programming of the flash memory requires a specific in-circuit emulator, the ADM-51 by Signum Systems
(www.signum.com) or the Flash Programmer (TFP2) available through Digi-Key (www.digikey.com) or Mouser
Electronics (www.mouser.com).
Chips may also be programmed before they are soldered to the board. Gang programmers suitable for high-
volume production are available from BPM Microsystems (www.bpmmicro.com).
In-Circuit Emulator: If firmware exists in the 71M6541F flash memory; it has to be erased before loading a new
file into memory. Figure 1-5 and Figure 1-6 show the emulator software active. In order to erase the flash
memory, the RESET button of the emulator software has to be clicked followed by the ERASE button.
To successfully erase the flash memory, the following steps have to be taken:
1) Disable the CE by writing 0x00 to address 0x2000
2) Write 0x20 to address 0x2702 ( FLSH_UNLOCK[ ] register in I/O RAM)
3) Reset the demo board (RESET button or power cycle)
4) Activate the ERASE button in the WEMU51 user interface
5) Now, new code can be loaded into the flash memory
Once the flash memory is erased, the new file can be loaded using the commands File followed by Load. The
dialog box shown in Figure 1-6 will then appear making it possible to select the file to be loaded by clicking the
Browse button. Once the file is selected, pressing the OK button will load the file into the flash memory of the
71M6541F IC.
At this point, the emulator probe (cable) can be removed. Once the 71M6541F IC is reset using the reset button
on the Demo Board, the new code starts executing.