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openFPGALoader
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speed up toggleClk

This commit is contained in:
Alexey Starikovskiy 2023-08-29 20:22:56 +03:00
parent ff755f9811
commit 077d730c63
1 changed files with 15 additions and 14 deletions
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29
src/ch347jtag.cpp
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@ -223,17 +223,12 @@ CH347Jtag::~CH347Jtag()
int CH347Jtag::_setClkFreq(uint32_t clkHZ)
{
unsigned i = 0, sl = 2000000;
if (clkHZ <= 2000000) {
_clkHZ = 2000000;
i = 0;
} else {
for (; i < 5; ++i, sl *= 2) {
if (clkHZ < sl) break;
_clkHZ = sl;
}
i--;
unsigned i = 0, sl = 1800000;
for (; i < 6; ++i, sl *= 2) {
if (clkHZ < sl)
break;
}
_clkHZ = sl;
if (setClk(i)) {
printError("failed to set clock rate");
return 0;
@ -280,7 +275,9 @@ int CH347Jtag::toggleClk(uint8_t tms, uint8_t tdi, uint32_t len)
uint8_t bits = 0;
if (tms) bits |= SIG_TMS;
if (tdi) bits |= SIG_TDI;
if (!bits && len > 7) {
return writeTDI(0, 0, len, false);
}
uint8_t *ptr = obuf;
for (uint32_t i = 0; i < len; ++i) {
if (ptr == obuf) {
@ -309,7 +306,7 @@ int CH347Jtag::toggleClk(uint8_t tms, uint8_t tdi, uint32_t len)
int CH347Jtag::writeTDI(const uint8_t *tx, uint8_t *rx, uint32_t len, bool end)
{
if (!tx || !len)
if (!len)
return 0;
unsigned bytes = (len - ((end)?1:0)) / 8;
unsigned bits = len - bytes * 8;
@ -320,7 +317,11 @@ int CH347Jtag::writeTDI(const uint8_t *tx, uint8_t *rx, uint32_t len, bool end)
while (tptr < txend) {
unsigned avail = sizeof(obuf) - 3;
unsigned chunk = (txend - tptr < avail)? txend - tptr: avail;
memcpy(&obuf[3], tptr, chunk);
if (tx) {
memcpy(&obuf[3], tptr, chunk);
} else {
memset(&obuf[3], 0, chunk);
}
tptr += chunk;
// write header
obuf[0] = cmd;
@ -351,7 +352,7 @@ int CH347Jtag::writeTDI(const uint8_t *tx, uint8_t *rx, uint32_t len, bool end)
uint8_t x = 0;
const uint8_t *bptr = &tx[bytes];
for (unsigned i = 0; i < bits; ++i) {
uint8_t txb = bptr[i >> 3];
uint8_t txb = (tx) ? bptr[i >> 3] : 0;
uint8_t _tdi = (txb & (1 << (i & 7))) ? SIG_TDI : 0;
x = _tdi;
if (end && i == bits - 1) {