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ecp5: Support for differential IO

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Signed-off-by: David Shah <davey1576@gmail.com>
This commit is contained in:
David Shah 2018-07-24 12:57:54 +02:00
parent f61e9e5609
commit 35a6bc496e
1 changed files with 15 additions and 1 deletions
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16
ecp5/bitstream.cc
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@ -258,6 +258,20 @@ void write_bitstream(Context *ctx, std::string base_config_file, std::string tex
std::string pic_tile = get_pic_tile(ctx, empty_chip, bel);
cc.tiles[pio_tile].add_enum(pio + ".BASE_TYPE", dir + "_" + iotype);
cc.tiles[pic_tile].add_enum(pio + ".BASE_TYPE", dir + "_" + iotype);
if (is_differential(ioType_from_str(iotype))) {
// Explicitly disable other pair
std::string other;
if (pio == "PIOA")
other = "PIOB";
else if (pio == "PIOC")
other = "PIOD";
else
log_error("cannot place differential IO at location %s\n", pio.c_str());
cc.tiles[pio_tile].add_enum(other + ".BASE_TYPE", "_NONE_");
cc.tiles[pic_tile].add_enum(other + ".BASE_TYPE", "_NONE_");
cc.tiles[pio_tile].add_enum(other + ".PULLMODE", "NONE");
cc.tiles[pio_tile].add_enum(pio + ".PULLMODE", "NONE");
}
if (dir != "INPUT" &&
(ci->ports.find(ctx->id("T")) == ci->ports.end() || ci->ports.at(ctx->id("T")).net == nullptr)) {
// Tie tristate low if unconnected for outputs or bidir
@ -270,7 +284,7 @@ void write_bitstream(Context *ctx, std::string base_config_file, std::string tex
std::string cib_wirename = ctx->locInfo(cib_wire)->wire_data[cib_wire.index].name.get();
cc.tiles[cib_tile].add_enum("CIB." + cib_wirename + "MUX", "0");
}
if (dir == "INPUT") {
if (dir == "INPUT" && !is_differential(ioType_from_str(iotype))) {
cc.tiles[pio_tile].add_enum(pio + ".HYSTERESIS", "ON");
}
} else {