Other Parts Discussed in Thread: MSP430F5529, , TPD2E001
Tool/software:
My original post, 1521187 with the same title, was becoming too long & convoluted, so closed it. I think I found 1 or 2 problems in my USB circuit: USB power, and XT2 complications.
I'm using the TI USB Developer Pack CDC example: C0_SimpleSend which builds, loads, and runs fine on the MSP430F5529 Launch Pad, using CCS v. 12.8.1.00005. I need to get it running on my custom SBC which uses the MSP430F5638 MCU. Just need to send data as text to a Host PC via USB. This example generally does what I need. Copied the above example into a new Workspace, changed project MCU from F5529 to F5638, and it builds fine in CCS but does not do anything when it runs.
There are USB circuit discrepancies between the Data Sheet (Table 7.1), and Start USB Fig. 8 docs. Also role and use of XT2 is not clear, 8 questions follow.
1 - Is VBUS, pin 80, internally connected to Vcc or does it need an external power connection?
Start USB, Fig. 8 does not show a power connection to VBUS
Data Sheet, Table 7-1, VBUS connect to power
2 - Is VUSB, pin 81, internally connected to Vcc or does it need an external power connection?
Start USB Fig. 8 , shows power connection to VUSB.
Data Sheet, Table 7-1, VUSB is LDO output, no power in
3 - User Guide Table 42-2 shows that 20 MHz XT2 is one of the few frequencies that are NOT supported.
Must I replace the XT2 crystal with a different supported frequency - up to 32 MHz?
Also set two dividers in code?
4 - According to Programmers Guide, p. 93, if XT2 is used for MCU, it is not available for USB?
5 - What is the correct PID value for the 5638? Programmers Guide, p. 33, shows 0x03FF but for which MCU, or is this an experimental value for any MCU?
6 - Not using the Zener diode on VBUS, a good idea, but not required?
7 - My ESD / EMI / RFI filter is USBUF02W6 not TPD2E001, that should not matter?
8 - Must run the Descriptor Tool for the 5638 and copy created files into this project?
