Commit Graph

96 Commits

Author SHA1 Message Date
Byron Lathi
ee97c4cbaa Add platform generation to build stage 2022-03-17 14:25:26 -05:00
Byron Lathi
2d49fe22a7 ignore .sopcinfo
This will be generated automatically when built.
2022-03-17 13:53:07 -05:00
Byron Lathi
2a1f8df54e Create SDRAM memory region 2022-03-17 13:37:34 -05:00
Byron Lathi
15e3ae9688 Add SDRAM controller (controller)
Turns out there are some issues with holding the chip select for the
SDRAM controller high for too long, so there is a simple 2-state fsm
which ensures that the chip select is only held for 1 clock cycle for
writes and for as long as it takes to read the data from sdram for
reads.
2022-03-17 13:31:56 -05:00
Byron Lathi
aa337c61d5 Create sdram platform 2022-03-15 23:45:57 -05:00
Byron Lathi
c0d7766bc6 Merge branch 'conio' into 'master'
Add conio

See merge request bslathi19/super6502!6
2022-03-15 15:03:19 +00:00
Byron Lathi
15b91dcc20 Add conio
Also removes print statements from the interrupt handler (except for the
button interrupt)
2022-03-14 22:20:15 -05:00
Byron Lathi
340f43103a Fix bug where A was overwritten in _uart_txb_block
If you wanted to transmit a value and then check what it was, you can do
that now.
2022-03-14 22:19:19 -05:00
Byron Lathi
a627d38778 Ignore all output files 2022-03-14 16:58:44 -05:00
Byron Lathi
ac3f5a0fca Merge branch 'uart-irq' into 'master'
Add UART Receive logic

See merge request bslathi19/super6502!5
2022-03-14 21:56:27 +00:00
Byron Lathi
8e161664bb Add uart_rxb
Once you receive a uart interrupt you can call this function to get the
received character.
2022-03-14 16:48:24 -05:00
Byron Lathi
59d2d4f601 Add receive logic to UART
The UART has a receive buffer which will fill up when it receives bytes.
Once the buffer is full, it raises the RX flag until the value is read
by the cpu.
2022-03-14 16:41:59 -05:00
Byron Lathi
ed18b381f3 Change "clkdiv" to "tx_clkdiv" 2022-03-14 15:22:18 -05:00
Byron Lathi
264263b0d9 Change "state" to "tx_state" etc. 2022-03-14 15:10:59 -05:00
Byron Lathi
b2344d986e Add UART interrupts
Currently an interrupt is triggered any time there is any activity on
the UART_RXD line, but later it will only trigger once there is data
ready to be read.
2022-03-14 14:57:45 -05:00
Byron Lathi
0316d047e3 Merge branch 'irqs' into 'master'
Add interrupt status register

See merge request bslathi19/super6502!4
2022-03-14 19:04:30 +00:00
Byron Lathi
f5dbe46060 Add irq_set_status
irq_set_status can be used to clear the irq status bit so that the
interrupt will stop occuring.
2022-03-14 13:34:33 -05:00
Byron Lathi
a5474b5ae5 Implement interrupt status register
Upon an interrupt, you can read from the interrupt status register to
see what caused the interrupt.
2022-03-14 13:30:01 -05:00
Byron Lathi
e012eb7d4d Exclude vectors from list of test objects
We do not need this, since there are no interrupts during tests.
2022-03-14 13:27:29 -05:00
Byron Lathi
e70fffb472 Add irq status register
Upon receiving an interrupt, the corresponding bit in the interrupt
status register will be set and an IRQ will be raised for the CPU. The
cpu can then respond to the interrupt and clear the interrupt by writing
back to the interrupt status register.
2022-03-14 13:16:09 -05:00
Byron Lathi
26070313f4 Ignore greybox_tmp 2022-03-14 13:15:20 -05:00
Byron Lathi
fe45331e7a Add interrupt handlers and redo vector locations
Most of these are taken from
https://cc65.github.io/doc/customizing.html, but modified to suit this
setup.
2022-03-14 11:54:43 -05:00
Byron Lathi
ff78fd0179 Connect Button 1 to cpu_irqb
A maskable interrupt can be generated by pressing button 1, the reset
button remains button 0.
2022-03-14 11:53:45 -05:00
Byron Lathi
5560b06c9f Merge branch 'uart' into 'master'
Add UART TX Module

See merge request bslathi19/super6502!3
2022-03-14 16:02:04 +00:00
Byron Lathi
4fb73f8e97 Update cs_testbench.sv
Add uart_cs and fix error messages
2022-03-14 10:56:15 -05:00
Byron Lathi
a671fda51c Add sample puts function
"Hello, world!" :)
2022-03-14 10:46:36 -05:00
Byron Lathi
cfcf94a875 Integrate uart controller into top level module
Adds new chip select for the UART, and a new entry in the data_out mux
for the UART.
2022-03-14 10:45:45 -05:00
Byron Lathi
da4d5f0fe7 Add uart tests 2022-03-14 00:47:26 -05:00
Byron Lathi
0b5ccf48b8 Add basic UART driver
This didn't have a chance to get tested so I hope it works.

There is not fancy stuff here, just write to the register and wait till
it is done.
2022-03-14 00:24:08 -05:00
Byron Lathi
b48438f6b2 Add write and puts tasks to the uart testbench
The write task will transmit a single byte, the puts task will transmit
a string of length n. These do not do any verification, you still have
to look at the output.
2022-03-14 00:04:04 -05:00
Byron Lathi
f8da9206d9 Refactor uart.sv to better allow cpu control
Added new signal tx_flag, which indicates whether the transmitter is
ready for new data.

Added status register, which when read will return the tx_flag bit, as
well as others that can be implemented.

Added new state IDLE, which resets the TX flag and allows new data to be
written.

Added code to allow for different baud rates, though it is still fixed
currently.
2022-03-14 00:00:55 -05:00
Byron Lathi
e063e9f6a3 Add basic UART device
So far the device only transmits the ASCII set on repeat, but will
become fully featured later.
2022-03-13 19:42:41 -05:00
Byron Lathi
5834f179d2 Ignore more modelsim files
Ignore all bak files and msim_transcript
2022-03-13 19:39:14 -05:00
Byron Lathi
36ff20e587 Update Makefile
Add source as comment in assembly listings.
2022-03-12 22:40:48 -06:00
Byron Lathi
45af469029 Merge branch 'hex_driver' into 'master'
Add full seven segment display driver

See merge request bslathi19/super6502!2
2022-03-13 04:23:11 +00:00
Byron Lathi
d229052ed6 Add hex tests 2022-03-12 22:17:41 -06:00
Byron Lathi
a6bcadab6e Fix bugs in sevenseg.s
Fixed bug where we forgot to restore x in _hex_set_8 if the idx check
fails. We did remember to restore it if the check passed.

Fixed bug where _hex_set_24 did not return 0.
2022-03-12 22:10:37 -06:00
Byron Lathi
1a9290b97b Implement hex_set_24 2022-03-12 21:55:17 -06:00
Byron Lathi
226a2972cc Implement hex_set_16 2022-03-12 21:49:47 -06:00
Byron Lathi
c8a7cc4153 Implement enable byte in sw 2022-03-12 21:46:08 -06:00
Byron Lathi
c7e8cc3798 Implement enable byte in hw 2022-03-12 21:45:30 -06:00
Byron Lathi
9bbfce23e2 Add driver for hex digits
This only includes the method to set the pairs of displays individually.
The functions to write a single 16 or 32 bit value have not been
implemented yet, nor has the mask function.
2022-03-12 21:26:19 -06:00
Byron Lathi
627b6a746a Add high pair of seven segment displays
This also increases the number of registers to 4, one more for the high
pair of displays, and a final one for a mask register which has not been
implemented yet.
2022-03-12 21:24:37 -06:00
Byron Lathi
b4ff993080 Merge branch 'first_start' into 'master'
Get the FPGA part working

See merge request bslathi19/super6502!1
2022-03-13 01:44:41 +00:00
Byron Lathi
79675ec773 Clean up modelsim folder 2022-03-12 19:41:08 -06:00
Byron Lathi
28836259e2 Don't track vcd files either 2022-03-12 19:34:43 -06:00
Byron Lathi
b7c92d3117 Don't track signaltap 2022-03-12 19:30:37 -06:00
Byron Lathi
ca4288df66 Change addr_decode test to use new io locations
Instead of whatever was there before, the new io locations are ram, rom,
and the hex digits.
2022-03-12 19:25:34 -06:00
Byron Lathi
08af30e823 Remove C tests
The previous tests are not useful anymore.
2022-03-12 19:25:01 -06:00
Byron Lathi
5106e50395 Update bootstrap code
Was missing some things like initializing the stack pointer, clearing
BSS, and things like that
2022-03-11 22:57:22 -06:00