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author | tmk <nobody@nowhere> | 2011-02-09 00:03:58 +0900 |
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committer | tmk <nobody@nowhere> | 2011-02-22 03:08:59 +0900 |
commit | acc974c64b1e17e6807133fdc50de5bb34aedda5 (patch) | |
tree | 7af7511a56d680a4d93b535c52891a8ffc15dd04 /pjrc/usb_debug.c | |
parent | 5552b5afeaa9ce7432f9ded3586984253f292d80 (diff) | |
download | firmware-acc974c64b1e17e6807133fdc50de5bb34aedda5.tar.gz firmware-acc974c64b1e17e6807133fdc50de5bb34aedda5.tar.bz2 firmware-acc974c64b1e17e6807133fdc50de5bb34aedda5.zip |
added protocol stack: pjrc, vusb
Diffstat (limited to 'pjrc/usb_debug.c')
-rw-r--r-- | pjrc/usb_debug.c | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/pjrc/usb_debug.c b/pjrc/usb_debug.c new file mode 100644 index 000000000..09048e0f1 --- /dev/null +++ b/pjrc/usb_debug.c @@ -0,0 +1,79 @@ +#include <avr/interrupt.h> +#include "sendchar.h" +#include "usb_debug.h" + + +// the time remaining before we transmit any partially full +// packet, or send a zero length packet. +volatile uint8_t debug_flush_timer=0; + + +int8_t sendchar(uint8_t c) +{ + static uint8_t previous_timeout=0; + uint8_t timeout, intr_state; + + // if we're not online (enumerated and configured), error + if (!usb_configured()) return -1; + // interrupts are disabled so these functions can be + // used from the main program or interrupt context, + // even both in the same program! + intr_state = SREG; + cli(); + UENUM = DEBUG_TX_ENDPOINT; + // if we gave up due to timeout before, don't wait again + if (previous_timeout) { + if (!(UEINTX & (1<<RWAL))) { + SREG = intr_state; + return -1; + } + previous_timeout = 0; + } + // wait for the FIFO to be ready to accept data + timeout = UDFNUML + 4; + while (1) { + // are we ready to transmit? + if (UEINTX & (1<<RWAL)) break; + SREG = intr_state; + // have we waited too long? + if (UDFNUML == timeout) { + previous_timeout = 1; + return -1; + } + // has the USB gone offline? + if (!usb_configured()) return -1; + // get ready to try checking again + intr_state = SREG; + cli(); + UENUM = DEBUG_TX_ENDPOINT; + } + // actually write the byte into the FIFO + UEDATX = c; + // if this completed a packet, transmit it now! + if (!(UEINTX & (1<<RWAL))) { + UEINTX = 0x3A; + debug_flush_timer = 0; + } else { + debug_flush_timer = 2; + } + SREG = intr_state; + return 0; +} + +// immediately transmit any buffered output. +void usb_debug_flush_output(void) +{ + uint8_t intr_state; + + intr_state = SREG; + cli(); + if (debug_flush_timer) { + UENUM = DEBUG_TX_ENDPOINT; + while ((UEINTX & (1<<RWAL))) { + UEDATX = 0; + } + UEINTX = 0x3A; + debug_flush_timer = 0; + } + SREG = intr_state; +} |