From b2438caec36bcd35606f16e52d28b011bba4d26b Mon Sep 17 00:00:00 2001 From: kittennbfive <58293822+kittennbfive@users.noreply.github.com> Date: Mon, 28 Sep 2020 14:49:35 +0000 Subject: update doc - UNTESTED on real hardware --- docs/constraints.md | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) (limited to 'docs/constraints.md') diff --git a/docs/constraints.md b/docs/constraints.md index 67c8ddd7..4917b33f 100644 --- a/docs/constraints.md +++ b/docs/constraints.md @@ -9,11 +9,18 @@ The iCE40 architecture supports PCF constraints thus: set_io led[0] 3 -and the ECP5 architecture supports a subset of LPF constraints: +and the ECP5 architecture supports a subset of LPF constraints (for details see Lattice Technical Note "FPGA-TN-02032 1.3"): LOCATE COMP "led[0]" SITE "E16"; IOBUF PORT "led[0]" IO_TYPE=LVCMOS25; - + IOBUF ... DRIVE=8; + IOBUF ... OPENDRAIN=ON|OFF; + IOBUF ... TERMINATION=50; + IOBUF ... DIFFRESISTOR=100; //for differential IO only + IOBUF ... CLAMP=ON|OFF; + IOBUF ... PULLMODE=UP|DOWN|NONE; + IOBUF ... SLEWRATE=FAST|SLOW; //outputs only + IOBUF ... HYSTERESIS=ON|OFF; ## Absolute Placement Constraints -- cgit v1.2.3 From c4244d967d5698ea5932ee7249d8de86eeb3260d Mon Sep 17 00:00:00 2001 From: David Shah Date: Thu, 1 Oct 2020 09:02:29 +0100 Subject: docs: Tidy up Signed-off-by: David Shah --- docs/constraints.md | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'docs/constraints.md') diff --git a/docs/constraints.md b/docs/constraints.md index 4917b33f..dead8780 100644 --- a/docs/constraints.md +++ b/docs/constraints.md @@ -13,9 +13,9 @@ and the ECP5 architecture supports a subset of LPF constraints (for details see LOCATE COMP "led[0]" SITE "E16"; IOBUF PORT "led[0]" IO_TYPE=LVCMOS25; - IOBUF ... DRIVE=8; + IOBUF ... DRIVE=4|8|12|16; // currently LVCMOS33 and LVCMOS33D only IOBUF ... OPENDRAIN=ON|OFF; - IOBUF ... TERMINATION=50; + IOBUF ... TERMINATION=50|75|150; IOBUF ... DIFFRESISTOR=100; //for differential IO only IOBUF ... CLAMP=ON|OFF; IOBUF ... PULLMODE=UP|DOWN|NONE; -- cgit v1.2.3 option value='author'>author

path: root/frontends/ast/ast_binding.cc

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