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lib.io: allow dir="oe".

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Although a dir="oe" pin is generally equivalent to dir="io" pin with
the i* signal(s) disconnected, they are not equivalent, because some
pins may not be able to support input buffers at all, either because
there are no input buffers, or because the input buffers are consumed
by some other resource.

E.g. this can happen on iCE40 when the input buffer is consumed by
a PLL.
This commit is contained in:
whitequark 2019-06-03 04:28:53 +00:00
parent 9ba2efd86b
commit 1eee7cd76f
2 changed files with 53 additions and 10 deletions
Download patch file Download diff file Expand all files Collapse all files

41
nmigen/test/test_lib_io.py
View file

@ -27,6 +27,19 @@ class PinLayoutCombTestCase(FHDLTestCase):
"o": ((2, False), DIR_NONE),
})
def test_pin_layout_oe(self):
layout_1 = pin_layout(1, dir="oe")
self.assertEqual(layout_1.fields, {
"o": ((1, False), DIR_NONE),
"oe": ((1, False), DIR_NONE),
})
layout_2 = pin_layout(2, dir="oe")
self.assertEqual(layout_2.fields, {
"o": ((2, False), DIR_NONE),
"oe": ((1, False), DIR_NONE),
})
def test_pin_layout_io(self):
layout_1 = pin_layout(1, dir="io")
self.assertEqual(layout_1.fields, {
@ -66,6 +79,19 @@ class PinLayoutSDRTestCase(FHDLTestCase):
"o": ((2, False), DIR_NONE),
})
def test_pin_layout_oe(self):
layout_1 = pin_layout(1, dir="oe", xdr=1)
self.assertEqual(layout_1.fields, {
"o": ((1, False), DIR_NONE),
"oe": ((1, False), DIR_NONE),
})
layout_2 = pin_layout(2, dir="oe", xdr=1)
self.assertEqual(layout_2.fields, {
"o": ((2, False), DIR_NONE),
"oe": ((1, False), DIR_NONE),
})
def test_pin_layout_io(self):
layout_1 = pin_layout(1, dir="io", xdr=1)
self.assertEqual(layout_1.fields, {
@ -109,6 +135,21 @@ class PinLayoutDDRTestCase(FHDLTestCase):
"o1": ((2, False), DIR_NONE),
})
def test_pin_layout_oe(self):
layout_1 = pin_layout(1, dir="oe", xdr=2)
self.assertEqual(layout_1.fields, {
"o0": ((1, False), DIR_NONE),
"o1": ((1, False), DIR_NONE),
"oe": ((1, False), DIR_NONE),
})
layout_2 = pin_layout(2, dir="oe", xdr=2)
self.assertEqual(layout_2.fields, {
"o0": ((2, False), DIR_NONE),
"o1": ((2, False), DIR_NONE),
"oe": ((1, False), DIR_NONE),
})
def test_pin_layout_io(self):
layout_1 = pin_layout(1, dir="io", xdr=2)
self.assertEqual(layout_1.fields, {