Grzegorz Daniluk authored 7 years ago and Tomasz Wlostowski committed 6 years ago

They finally don't help much and they break simulation as Modelsim complains
about types conversion.

Peter Jansweijer authored 11 years ago and Grzegorz Daniluk committed 10 years ago

The simulator is crashing at the end of the LM32 startup code when it tries to
access the highest RAM location (at the stack pointer). After this access, the
LM32 verilog code already increments the address to be prepared for the next
cycle, which will never actually happen because you are at the end of the RAM.
It is this address increment in verilog that is one address outside the defined
RAM array for which the simulator complains and terminates. The actual
synthesized code is perfectly fine; no accesses outside RAM.

The RW ordering on address conflict varies by platform.
Some platforms only support some options.
Most of the dprams in WR are portable and don't depend on the order.
This new option allows a core to specify that it does not care what
the result of a RW conflict is, and thus work on more platforms.

For Xilinx, "dont_care" = "read_first", the old default.

In the past we used a generic to set the initial memory contents on altera.
Unfortunately, quartus compiles big generics slowly (read: hours).
Now we can load from a .mif file instead, which is much faster (seconds).
Thus, this old option is no longer needed.

genrams/xilinx/generic_dpram: made two separate versions for memories with both ports clocked with the same signal and with independent clocks

This is to prevent ISE from interpreting the single-clock template as a dual-clock one, which may result in read-after-write memory content corruption on Spartan-6/Virtex-6 FPGAs.

Tomasz Wlostowski authored 13 years ago and Tomasz Wlostowski committed 12 years ago

Genrams is a collection of synthesizable RAM/FIFO providing identical interface and features on different FPGA platforms.

Quartus will not process a 'file_open' call during synthesis,
so we can instead initialize the RAM with a vhdl constant.

This reverts commit ae005148.