+ add custom interactive script to insert a buffer on user_clk output
and have a large buffer on core_clk
~ change pdn config to match top level
~ change sdc
~ change openlane configuration
~ reimplement based on updated views of the macros
~ change interactive script to call label_macro_pins
~ extract all spef and sdf corners using timing-scripts repo
!important same work arounds as before
~ update interactive script for chip_io.v for recent openlane
~ update config.tcl for recent openlane
~ add a verilog stub for sky130_fd_io__top_xres4v2 as
the io verilog models are not readable by yosys
- reimplement using a sparecell
- reimplement using newest open_pdks
!important using openlane pre odb with some local patches which
most if not all are merged in the current head of openlane however
still takes effort to update the interactive script to be latest
openlane compatible
!important override abstract lef generated by openlane. openlane
generates lef and mag that contain def BLOCKAGE layers that cause
congestions during top level routing
~ update the following views:
def
mag
verilog
spef(all corners)
+ add the ability to override the interactive script filename
+ add the ability to run openlane regression using regression.config
file
~ change GRT ADJUSTMENT values
~ change pointers to some files for workarounds
!important the interactive script still needs updates
!important this was done using old openlane v0.22 and its matching
pdk
!important known workarounds:
- a custom techlef is used where large metal spacing rules are the
only ones present to avoid violations by the router
- some odd behaviour happening when a macro has a lef view
with a non zero origin. so the power routing cell is (temporarily)
modified to have a zero origin and its placement has been shifted
which doesn't match the power routing mag.
- the old openlane doesn't generate multi spef corners. they
are generated using timing-scripts repo
- rtl updated
~ add one column to the right to pass placement congestion
~ density adjusted (probably has no effect)
+ manually add isosubstrate layer in mag and gds from older iterations
!important still need to run dynamic simulations
!important depends on some updates to openlane
!important need to be able to recreate using newer openlane versions
the left hand side of caravan from gpio_defaults_block_14 to
gpio_defaults_block_25. Otherwise, the script that generates the
custom user configuration won't be able to change the defaults
for GPIO 25.
- high level changes:
* add larger buffers on output ports
* add buffers on input ports
* adjust sdc file increasing output load and setting a high transition
- detailed changes:
* add interactive script for openlane where the order of events is a bit shuffled
- to add obstruction before pdn
- to manually insert buffers on some ports
- to manually remove buffers inserted by synthesis on for example serial_clock_out
* change openlane config adding extra row and columns to increase the space and fit the
added buffers
* change config to enable buffering
* increase density for better placement?
* change the cell exclude list. some excluded cells didn't make sense
* ef decap cells break dynamic sims?
* add custom pdn script for to duplicate the old pdn
- misc changes:
* fix openlane makefile to properly detect interactive script
!important still need to run dynamic simulations
!important depends on some updates to openlane
does not pass through an inverter, so that the input can remain
unconnected. Rewired the existing implementation to use an
alternative gate that has an inverting input so that the
user_gpio_out signal can be left undriven when the GPIOs are in
the management enable state. This is a simple logic refactoring
and does not change the logic function. The manual rewiring has
been confirmed by LVS, but at least one GL simulation should be
run to confirm that the logic function remains the same as before.
Passant
kareem
mo-hosni
Marwan Abbas
passant5
Mohamed Hosni
Mohamed Shalan
R. Timothy Edwards