ZSP Flash Procedures
Flash memory programming through boundary scan

Initialization Procedure

Displaying Flash Memory

Saving Flash Memory

Erasing Flash Memory

Programming Flash Memory

Steps for Proper Operation

1

Configure the evaluation board for flash programming; this requires enabling Vpp voltage to the flash device.

• For EB402, install the JP20 jumper shunt.
• For EB403, move the dip switch SW2 - position 6 to the 'On' position.

To save the current version of the monitor image, activate the other half of the flash device:

• For EB402, change JP15
• For EB403,  change SW2- position 4

2

In the IDE, under Options - Open Connection, initialize the connection to the target ZSP device; use ZSP-USB-JTAG as an emulator and select ZSP400 as the target device. If the device has a recognizable JTAG IDCODE, initialization can be done by simply clicking on the Query button in the "Open connection" dialog. Note, if the connected target device does not have known JTAG IDCODE to identify it, a configuration file must be executed via the command window to populate the Target Select field.

3

Verify that the correct BSDL file is associated with the active target device(s). From within the IDE command window, enter the "JTAG" command, with no parameters; this will list all devices configured on the JTAG's boundary scan chain using corresponding BSDL files.

To associate a BSDL file with a specific device, from within the IDE  command window, enter the following command: 

JTAG devNum BSDL filename

• devNum is a 0 based index counting from the last device (the last device is the one whose TDO pin is the one connected to the JTAG emulator connector)
• BSDL is a parsing key instructing that following parameter will be a BSDL file name
• fileName is the name of the file describing the target device

Sample command: 
    JTAG 0 BSDL zsp402zx.bsdl

4

From within the IDE Command window, assign BSDL signal names to the pins that control the memory functions of the target memory device. For flash programming, the following signal parameters/configurations are required:

• ADDR[width] - for pins controlling flash device address lines. If the device is not using full address bus to control flash memory, it can be limited with optional "width" parameter
• DATA[width] - for pins connected to the data bus of the flash. These pins need to be bi-directional (see corresponding BSDL file)
• WRITE - for flash write strobe (can be defined as active low or high
• READ - for flash read strobe (can be defined as active low or high)
• CS - flash chip select (can be defined as active low or high)

Note that if the ADDR or DATA bus do not have a "bus" representation in the BSDL file, then the bus needs to entered as separate signals. For strobe signal functions, multiple pins can be can be defined and specified to perform a given function by repeating particular function in the definition.

5

Verify the boundary scan integrity by executing IDCODE command from within the IDE Command window. This command should return a 32-bit number matching the 32-bit ID in the BSDL file for this device. If the IDCODE command returns all 0s, or all 1s, the connection is faulty. For the purposes of programming an external Flash memory device, an operating clock for the target device is not required.

6

Initialize boundary scan operations by preloading (capturing) a valid data pattern into the data buffers using the JTAG SAMPLE/PRELOAD command, and switching into the EXTEST operation mode

7

From within the IDE Command window, enter the FLASHMOD command to select the Flash programming mode. There are two predefined modes and one user mode:

• 0 use mode (default)
• 1 AMD mode (4 accesses per single word write)
• 2 Micron mode (2 accesses per single word write)

8

Verify if the flash device can be accessed by issuing the FLASHID command. This should return manufacturer and device identification numbers specific to each flash memory device

1

After Erase and Programming operation, flash device is left in the last executed command mode, so reading back from the flash device, will return the last status word. To change back into the "read" mode, the FLASHID command can be used. Also, the target device is left in the EXTEST mode, so external reset will not work. To disable the EXTEST mode, IDCODE command can be used to change the current JTAG state back to RTI.

2

The whole above procedure is available as a single command file for two ZSP evaluation boards: EB402 and EB403. All necessary files are available below

3

To use one of the command files, it is necessary only to open connection to the target device by openning the "Open Connection" dialog, executing "Query", and accepting detected device. Then from the command window, enter the name of the command file for the updated evaluation board: FlashEb402 or FlashEb403