scampos 0 Posted December 16, 2015 Share Posted December 16, 2015 I'm trying to understand the two possible configurations of the headers on the MSP430G2, rev 1.5, at the top near the border between the emulator and the uart. The silk screen seems to indicate that one configuration is appropriate for hardware uart, and the other configuration is appropriate for software uart. I'm wondering, why does it matter? Whether using a software uart or chip with a hardware uart on board, either way doesn't the TX pin of the MSP still need to go to the RX pin of the emulator (likewise for RX-TX) in order to get data back and forth from a PC? And when the direction is rotated, this seems even stranger since it looks like we're connecting TX-TX and RX-RX. So what's really going on here? Thanks Quote Link to post Share on other sites
Rei Vilo 695 Posted December 16, 2015 Share Posted December 16, 2015 One is for G2553 and the other for G2452. Quote Link to post Share on other sites
yosh 121 Posted December 16, 2015 Share Posted December 16, 2015 Basically it's something like this: In this way you can "switch" the pins for HW or SW UART by just rotating the two jumpers. enl and reaper7 2 Quote Link to post Share on other sites
enl 227 Posted December 16, 2015 Share Posted December 16, 2015 The dedicated hardware pins, on the processors that have a hardware UART, such as the 2553, are swapped from the pins used by the software serial on the non-hardware UART devices. One position is for use with hardware UART *or* software serial that uses the same Tx and Rx as the hardware UART. The other position is for use with the TI software serial Tx and Rx. Why are they different? I don't know. scampos 1 Quote Link to post Share on other sites
NoPinky 4 Posted December 16, 2015 Share Posted December 16, 2015 I think I understand, but why don't they keep it at the same pins (software wise)so it's pin compatible? Just du make sure that the user is always aware that he is using hardware UART or software UART? Quote Link to post Share on other sites
scampos 0 Posted December 16, 2015 Author Share Posted December 16, 2015 The dedicated hardware pins, on the processors that have a hardware UART, such as the 2553, are swapped from the pins used by the software serial on the non-hardware UART devices. One position is for use with hardware UART *or* software serial that uses the same Tx and Rx as the hardware UART. The other position is for use with the TI software serial Tx and Rx. Why are they different? I don't know. Thank you for fully answering the question. Quote Link to post Share on other sites
Rei Vilo 695 Posted December 16, 2015 Share Posted December 16, 2015 G2553 and G2452 have pins RX and RX swapped. Have a look at the pins maps at http://energia.nu/pin-maps/guide_msp430g2launchpad/ Quote Link to post Share on other sites
enl 227 Posted December 17, 2015 Share Posted December 17, 2015 I think I understand, but why don't they keep it at the same pins (software wise)so it's pin compatible? Just du make sure that the user is always aware that he is using hardware UART or software UART? No idea why the pins are swapped. If I were to make a guess, the G series software came before the hardware UART, and the way the hardware modules worked out ended up with exchanging the pins. I doubt it has anything to do with making sure the user knows what they are working with. More likely it has to do with parallel development between the software side and hardware side, and the use of standard macro cells and compatibility with previous devices for port assignment and hardware blocks, but that is only a guess. Quote Link to post Share on other sites
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