TMS320C2834x checks below four pins at the reset to decide the booting mode.
MODE | GPIO87 XA15 |
GPIO86 XA14 |
GPIO85 XA13 |
GPIO84 XA12 |
Booting mode |
E | 1 | 1 | 1 | 0 | SCI-A boot (for RAM booting) |
D | 1 | 1 | 0 | 1 | SPI-A boot (for flashrom booting) |
easyDSP activates both /BOOT and /RESET
pins low for RAM booting. And it activates only /RESET pin low for the menu
'DSP>Reset DSP'. So please connect easyDSP as below so that easyDSP can select
appropriate RAM booting mode (SCI-A).
Blue box of above table is the recommendation for flashrom booting. Hardware
preparation is your task.
( SCI-A boot @ RAM booting. SPI-A
boot
@ flashrom booting )
And please
note belows.
- SPI-A is used for easyDSP. You can't
use SPI-A for your purpose.
- power pin (#4) of
easyDSP 5x2 header should be connected to 3.3V
- TX/RX pins are directly connected to MCU pins
- In case there is a reset IC between
easyDSP /RESET and MCU /XRS, it should transfer easyDSP /RESET signal to MCU /XRS
within 0.5sec
- In case you insert buffer IC between easyDSP
header and MCU, place buffer IC directly to easyDSP header so that all resistors
can be connected to directly MCU
- /BOOT pin is connected via 2kΩ series resistor
- /RESET pin is
connected to reset generation circuit of MCU
board
(Time duration of /RESET pin is around 500msec)
- In case you use pull-up resistor to each pin, the value
of pull-up resistor should be higher than a few kilo ohm since there is 100Ω series resistor inside easyDSP
pod
Please be careful when you use
your own pull-up or pull-down resistor on the easyDSP signal pins. Please use
appropriate filter circuit to your reset generation circuit to prevent
unintentional reset generation.
Caution !!
When you select menu 'MCU'>'Reset MCU', only /RESET pin is
activated low. /BOOT is still high at that time.
Therefore don't use this menu if you are not ready to use SPI-A boot mode.