So I'm creating a new RT1060-based design, and I want to provide two Ethernet ports. We're using SDRAM, so the entire GPIO_EMC bank is unavailable. This means that for ENET 2 I have to use GPIO_B0_12 through GPIO_B1_03 (if I don't want to overlap USDHC1 on GPIO_SD_B0_00-05). Unfortunately, that takes away LCD_DATA[8-15] and leaves only LCD_DATA[7-0] and the four control signals, which is annoying because that appears to complicate connecting the LCDIF to an HDMI transmitter IC.
I know it's possible to get the LCDIF to drive an 8-bit bus with 24-bit pixel data; that's illustrated in Figure 35-4 in the reference manual, where it kicks out bytes B, C, and D on three separate clocks. Unfortunately, I can't seem to find an HDMI/TMDS transmitter that would accept such a bus interface.
- The Analog Devices ADV7513 seems to be a close match, but according to the programming guide it will only accept 2 clocks worth of pixel data (not 3), and it only accepts RGB data in a single-clock fashion. (Same for the ADV7511W and its programming guide.)
- The Texas Instruments TFP410 would also seem to be a candidate, but it accepts only a 12-bit or 24-bit input bus, no option for 8-bit. And the 12-bit mode is DDR (latches on both rising and falling edge).
- There's an NXP TDA19988 part out there, but there's very little info available about it; here's a Digi-Key link, and here's a forum thread link. Unfortunately, it only appears to offer 12-bit or 24-bit bus input, not 8-bit.
Is anyone aware of a solution that will take an 8-bit TTL/CMOS input and generate an HDMI/DVI/DisplayPort output? I realize that I could probably use any of the above chips if I just put a little FPGA between the RT1060's 8-bit LCD bus and the 24-bit HDMI transmitter input bus, and have the FPGA accept three clocks' worth of data before clocking all 24 bits out to the HDMI chip. Just wondering if there's a single-chip solution for this. Thanks.
David R.
