01-02-2025, 03:24 PM
The new [production] versions of the boards for the 2 models have lots of changes from the earlier prototypes, and in particular
the FPGA board. As a result there has been quite a bit of firmware and FPGA logic changes that needed to be made before I could test out
the new versions.
For example, the on the FPGA board the changes have been:
2Mb SRAM for main memory is now 32Mb SDRAM (on a different chip select from the MC68SZ328 processor with more initialisation needed)
Memory addressing changes, with different configuration requirements etc. etc.
Addition of Flash ROM to boot from (rather than the small embedded boot rom within the FPGA logic.
HDMI & I2S sound chips onboard now.
This week has been spent making all those changes, and I'm very pleased to say that the new version of the FPGA board is working really well.
Most of the hardware on the board is now proven out (with the exception of the Keyboard, Mouse & I2S sound interfaces).
Below is a picture of the new FPGA board in the 'Test Fixture / Production Programming jig' with power in and HDMI out attached.
Included in the new design is a way to reload the boot flash if it ever fails during a power off event during an update.
In the pic you can see nice crisp screen display, testing the FLASH ROM, reading the flash image in from SDcard etc.
Very happy with the progress. More to come.
the FPGA board. As a result there has been quite a bit of firmware and FPGA logic changes that needed to be made before I could test out
the new versions.
For example, the on the FPGA board the changes have been:
2Mb SRAM for main memory is now 32Mb SDRAM (on a different chip select from the MC68SZ328 processor with more initialisation needed)
Memory addressing changes, with different configuration requirements etc. etc.
Addition of Flash ROM to boot from (rather than the small embedded boot rom within the FPGA logic.
HDMI & I2S sound chips onboard now.
This week has been spent making all those changes, and I'm very pleased to say that the new version of the FPGA board is working really well.
Most of the hardware on the board is now proven out (with the exception of the Keyboard, Mouse & I2S sound interfaces).
Below is a picture of the new FPGA board in the 'Test Fixture / Production Programming jig' with power in and HDMI out attached.
Included in the new design is a way to reload the boot flash if it ever fails during a power off event during an update.
In the pic you can see nice crisp screen display, testing the FLASH ROM, reading the flash image in from SDcard etc.
Very happy with the progress. More to come.