Hello Friends, I'm new to microcontrollers, but I have one question. Is it possible to write new code (SAM-BA) in this old device to enable SPI module to read this card? If possible can someone help me? New SD card generation is Low Voltage 1.8v and I'm trying to program a reader, this Jlink has two Low-level converts from 3.3 to 1.8v. That's why I'm trying to use it. The pic is just to show the ideia! Ps: I don't understand programming (make code) But learned to use SAM-BA. Thanks in advantage
Djalma F. wrote: > New SD card generation is Low Voltage 1.8v Nope. Voltage for SPI mode (and 25 MHz SD modes) is still 3.3 Volts. And I would not trust your setup to run more than the default 25 MHz - maybe even less. Flying cables are bad for signal (and power) integrity. LibJaylink - as used in OpenOCD - can send raw JTAG sequences IIRC. This could in theory be (ab)used in order to implement SPI communication with the SD card, eliminating the need to re-program the JLInk device altogether. One problem: I don't know whether the JTAG timing matches SD's SPI timing requirements. Try running low speed first. Also note that SD cards come up in open drain mode and need a pullup resistor on the MISO line.
Thanks for answer! Well, you're right about 3.3v and 25Mhz in SDcards. This Jlink is out of use but still working. My desire is to change the internal software to read and write SD card using SPI inside module. This Box has two ALVC164245 (low Shifting Transceiver) Later I can use it to implement 1.8V or 3.3V (even for eMMC module reader). I'd like to run this in Linux. If this Jlink isn't supporting for this, can you help fine other "developer board that works for this purpose? I need this output as pic bellow. Thanks Djalma, Brazil +55 19982290220