problems that had been fixed recently in caravel, and which cause
the caravan testbench to break, but which were not noticed; (2)
corrected the count of gpio_control_block modules, which was one
off, with two of them overlapping (not sure how that even passes
simulation, but it did); (3) fixed a power connection in the
caravel chip_io, which should have caused chip_io to fail LVS,
so apparently LVS was not run on chip_io. . .
got removed from its net by a chang in the LEF view of an I/O pad, and
a lack of declaration of an array to attach to pwr_ctrl_out in the
verilog, which is valid verilog but netgen can't know the bus size
without the no-connect net being declared. The remaining issue has to
do with separation of ground domains in the mgmt_protect block.
(clock -> clock_core in caravel_clocking, VPWR -> vccd_core and
VGND -> vssd_core in the instances of modules that were pulled from
the management SoC to the top level).
fixed by moving from after the managment protect to before it, but
an inversion of the signal was missed, leading to an incorrect
wb_rst_i passed to housekeeping. (2) Revised the method to load
the serial GPIO data chain from a 2-pin, I2C-like method to a
more straightforward 3-pin method with separate reset, clock, and
load pins. The load pin propagates through the chaing like the
other two. Added a bit-bang signal for the load signal as well.
(3) Added an implied buffer after the data output of the GPIO
control block to ensure that the data arrives at the next control
block after the clock, to prevent hold violations.
incorrectly assigned to the clock on the user side of the managment
protect block, causing it to be undefined when the user area power
supply is down. The "hkspi_power" testbench which tests using the
housekeeping SPI while the user area power is grounded now works
correctly.
an unconnected wishbone bus (unconnected inputs). Added the missing
signals for the user IRQ enables to management protect (which have
to come from the management SoC).
Tim Edwards