Command w, Command d | Ricoh A741 specification

bit 2 = Copier computed checksum error in command from controller.

bit 1 = Status from copier violated timing constraints.

bit 0 = Command from controller violated timing constraints.

So, for example, if the YY byte had a value of 08, this means that the controller computed a checksum error in the status that was just sent from the copier. This byte can be cleared by issuing an “i” command as described in the Command: “i” section.

16.9Command: “v”

This command will return the controller version number from the Littlebear controller. It is in the form:

Version return bytes (hex): XX XX XX XX XX XX XX MJ XX MN Success retrieving version major:MJ (#) minor:MN (#)

Where XX are HEX values representing ASCII letters, and MJ and MN are HEX values representing ASCII numbers for the major and minor version numbers. LBTEST does not decode the ACSII letters but it does decode the ASCII numbers and displays them on the second line. Decoded, the current HEX bytes returned from this command form this ASCII line: #.#

16.10Command: “w”

This command is similar to the “r” command, but is used to write a register in the controller address space. After “w” is entered, LBTEST will prompt for the address to be written, then will prompt for the value to be written to the address. A two-byte HEX address is expected, then a one-byte HEX value. For example, to write a B4 to the register at address 8081h, enter 8081 when prompted for the register value, then enter B4 when prompted for the value to write to this register. To confirm the value just written, you may issue the “r” command to check the current value.

However, if the register just written is not writable, invalid data may be seen when reading the register back. Caution should be used when using this command, as many registers will affect the controller or copier operation.

16.11Command: “d”

This command writes test data to the Littlebear on-board FIFOs. LBTEST will prompt for how many bytes are to be written. This value can be from 0 to 200000 decimal. LBTEST will write data to the FIFOs beginning at the address currently pointed to by the controller. The test data starts with 00 HEX and continues until FF HEX. At this point, the data starts over at 00 HEX. In order to see what data was actually written to the FIFOs, it is necessary to use the next command (Read FIFOs). Note that LBTEST will display that a register is being written during this command. This register needs to be written with a certain value so that data is not clocked out of the FIFO so that it can be read back using the “f” command. LBTEST does this automatically and there is no need to write any registers manually.

A741

Print Server Manual