Vergil_Wong/lib_xua
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Add comments. Remove unnecessary variables.

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This commit is contained in:
Russell Gallop
2011-08-02 17:46:11 +01:00
parent 13835851b3
commit 6801d7a7c2
1 changed files with 16 additions and 21 deletions
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37
module_usb_midi/src/usb_midi.xc
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@@ -17,6 +17,7 @@ static unsigned makeSymbol(unsigned data) {
static unsigned bit_time = XS1_TIMER_MHZ * 1000000 / (unsigned) RATE;
static unsigned bit_time_2 = (XS1_TIMER_MHZ * 1000000 / (unsigned) RATE) / 2;
// For debugging
int mr_count = 0;
int th_count = 0;
@@ -84,8 +85,7 @@ void usb_midi(in port ?p_midi_in, out port ?p_midi_out,
int wrptr = 0;
unsigned rxPT, txPT;
int midi_from_host_overflow = 0;
int space_left;
int space_left;
//configure_clock_rate(clk_midi, 100, 1);
@@ -105,10 +105,7 @@ void usb_midi(in port ?p_midi_in, out port ?p_midi_out,
p_midi_out <: 1; // Start with high bit.
// printstr("mout0");
#endif
while (1) {
select
{
@@ -131,6 +128,7 @@ void usb_midi(in port ?p_midi_in, out port ?p_midi_out,
case isRX => t2 when timerafter(rxT) :> int _ :
if (rxI++ < 8)
{
// shift in bits into the high end of a word
unsigned bit;
p_midi_in :> bit;
rxByte = (bit << 31) | (rxByte >> 1);
@@ -189,7 +187,8 @@ void usb_midi(in port ?p_midi_in, out port ?p_midi_out,
uout_count++;
outputted_symbol = outputting_symbol;
// have we got another symbol to send to uart?
if (rdptr != wrptr) {
if (rdptr != wrptr) { // FIFO not empty
// Take from FIFO
outputting_symbol = symbol_fifo[rdptr];
symbol = makeSymbol(symbol_fifo[rdptr]);
rdptr++;
@@ -243,7 +242,6 @@ void usb_midi(in port ?p_midi_in, out port ?p_midi_out,
int event;
unsigned midi[3];
unsigned size;
int valid;
// received data from host
event = byterev(datum);
mr_count++;
@@ -267,19 +265,14 @@ void usb_midi(in port ?p_midi_in, out port ?p_midi_out,
{midi[0], midi[1], midi[2], size} = midi_out_parse(event);
for (int i = 0; i != size; i++) {
// add symbol to fifo
unsigned sym = midi[i];
int new_wrptr = wrptr + 1;
if (new_wrptr > USB_MIDI_DEVICE_OUT_FIFO_SIZE - 1) {
new_wrptr = 0;
symbol_fifo[wrptr] = midi[i];
wrptr++;
if (wrptr > USB_MIDI_DEVICE_OUT_FIFO_SIZE - 1) {
wrptr = 0;
}
symbol_fifo[wrptr] = sym;
wrptr = new_wrptr;
}
space_left = rdptr - wrptr;
space_left = rdptr - wrptr;
if (space_left < 0)
space_left += USB_MIDI_DEVICE_OUT_FIFO_SIZE;
@@ -289,7 +282,8 @@ void usb_midi(in port ?p_midi_in, out port ?p_midi_out,
else {
midi_from_host_overflow = 1;
}
// Start sending from FIFO
if (wrptr != rdptr && !outputting) {
outputting_symbol = symbol_fifo[rdptr];
symbol = makeSymbol(symbol_fifo[rdptr]);
@@ -300,11 +294,12 @@ void usb_midi(in port ?p_midi_in, out port ?p_midi_out,
if (space_left > 2 && midi_from_host_overflow) {
midi_from_host_overflow = 0;
midi_send_ack(c_midi);
}
}
#ifdef MIDI_LOOPBACK
handle_byte_from_uart(c_midi, mips, cable_number, got_next_event, next_event, waiting_for_ack, symbol);
#else
// Start sending byte (to be continued by outputting case)
p_midi_out <: 1 @ txPT;
t :> time;
time += bit_time;