Undocumented registers must be used as described inside the part of the RISC OS PRMs which describes DeviceFS_CallDevice. Regard all undocumented registers in range R0-R9 as reserved.
Operation | Register | Value | Meaning |
---|---|---|---|
Reset | R0 | 1<<31 + 0 | Resets the FTDI chip to defaults but not the device |
Flowcontrol Characters | R0 | 1<<31 + 1 | Sets and read XON/XOFF flowcontrol characters |
R3 | New XON character at entry. Old XON character at exit. | ||
R4 | New XOFF character at entry. Old XOFF character at exit. | ||
Read Modem Status | R0 | 1<<31 + 2 | Read modem status |
R3 | Contains modem status at exit. See FTDI documentation for explanation of the modem status. | ||
Set Event Character | R0 | 1<<31 + 3 | Set event character |
R3 | New event character at entry. See FTDI documentation for explanation of the event character. Usually usage of event characters is disabled. Setting the character enables usage. You canīt disable usage afterwards until a chip reset is performed. | ||
Set Error Character | R0 | 1<<31 + 4 | Set error character |
R3 | New error character at entry. See FTDI documentation for explanation of the error character. Usually usage of error characters is disabled. Setting the character enables usage. You canīt disable usage afterwards until a chip reset is performed. | ||
Latency Timer | R0 | 1<<31 + 5 | Read or set latency timer |
R3 | 0 is a forbidden value for the latency timer. Therefore this value is used to read the value of the latency timer into R3 at exit. Every other value writes the latency timer. See FTDI documentation for explanation of the latency timer. | ||
Set Bit Mode | R0 | 1<<31 + 6 | Sets FTDI chip Bit mode |
R3 | New FTDI chip Bit mode. The operation might failed because not every FTDI chip implements every mode and the driver is not supported every mode. In fact in the moment the driver supports only one mode:
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Get EEPROM | R0 | 1<<31 + 7 | Read content of the EEPROM which is inbuild in some FTDI chips |
R3 | Pointer to memory to hold the EEPROM content | ||
R4 | Bytes to read from EEPROM | ||
R5 | Offset into EEPROM to position to read from. | ||
Set EEPROM | R0 | 1<<31 + 8 | Sets FTDI chip Bit mode (Allowance must be set inside configuration) |
R3 | Pointer to memory holding the data to be written to the EEPROM. The driver knows the EEPROM size and so all data will be written in one go. | ||
Erease EEPROM | R0 | 1<<31 + 9 | Ereases the content of the EEPROM (Allowance must be set inside configuration) |