kb1gtt wrote:I would wager a guess that the chips general functions can be routed reasonably well. For example, going CW around the header we generally have analog to the left top side of the header. Then misc digital IO (DIO) along the bottom like USB, SPI and CAN are along the bottom of both headers. Then digital signals like injectors and spark signals are on the top right side of the header.
Maybe they could be routed reasonable well. But, if you look at the pins on the TMS570LS3137 (most other TMS570LSxxxx are very similar), the pins don't lay out the same way. (datasheet linked earlier). Multiple layers is probably required, or at least highly suggested, in order to maintain some semblance of compatibility with the Frankie board.
This separation of AN, GPIO and DIO are a reasonably commonly grouped by the chip MFG. If the grouping of these general features in a clock wise (CW) fashion around the chip, starts with AN, DIO, to GPIO, then we are in fat city. However if it's AN/GPIO/DIO then we would need to flip the chip to the other side of the board. If they are not grouped, then we could be in for a challenge.
By default, on the LS3137 (most other 144 pin TMS570 are very similar) pins are arranged around the chip:
... communications (SPI, CAN, LIN, FlexRAY, et cetera): 1-5, 13,14, 32, 37, 40, 51-55, 89-100, 105, 126, 128-133, 142.
... analog / ADC: 58-86.
... GPIO: 9, 14, 16, 22.
... N2HET: 6, 15, 23-25, 30, 31, 33, 35, 36, 38, 39, 41, 91, 92, 106, 107, 118, 124, 125, 127, 139-141.
... the remaining pins are VCC (1.2v), VCCIO (3.3v), VSS (ground), and error / status pins.
Perhaps a picture of the chip with some blobs of color to show AN/GPIO/DIO would help show how routing issues might be dealt with. I'd love to volunteer for such a picture, however I'm ignorant about these chips so it would be a large amount of work and I feel I wold be best used focusing on other priorities. ....
tms570ls3137_PINS.xlsx
Default assignments are bold and colored differently than alternate functions.