AM335x FAQ

Some frequently asked questions (and answers!) relating to AM335x:

Q: Does AM335x support MMC boot with MMC versions greater than v4.3?
A: Yes. JEDEC standard requires MMC devices to be backwards compatible.

Q: Is a JTAG header installed on the AM335x Starter Kit (TMDSSK3358)? If not, how can I add one?
A: The TMDSSK3358 is shipped without the JTAG header installed since the XDS100V2 via USB is expected to be used for JTAG debugging. To add one, follow the instructions found on this how-to wiki article: How to install a JTAG connector on the AM335x Starter Kit.

Q: How do I connect an 18-bit display to the 24-bit LCD interface of the AM335x?
A: Connect the 6 color bits from the LCD to the upper 6 bits of each color channel. Connect the remaining bits to ground.

Q: Can the unused pins of a peripheral interface of the AM335x be used as GPIO?
A: Yes. Pad Control Registers control the signal muxing and other aspects of each I/O pad. Refer to the AM335X Technical Reference Manual, section 9.2.2 Pad Control Registers for more information.

Q: Why don't read operations work on AM335X master SPI and I2C interfaces and GPMC in synchronous read mode?
A: On AM335X peripherals on which the processor provides the peripheral clock (SPI master, I2C master, GPMC sync. mode, maybe others too), RXACTIVE (bit 5 in the Pad Control Register) should be set to 1 (Receiver Enabled) for the pin which sources the peripheral clock. This is necessary for read operations re-timing.