add the ability to include additional data at the end of bitstream image and prepare an example, that reads thic data through SPI and displays it

1 files changed, 142 insertions, 0 deletions

diff --git a/examples/example3b_spi_tclasm/instructions.s.tcl b/examples/example3b_spi_tclasm/instructions.s.tcl
new file mode 100644
index 0000000..294a73e
--- /dev/null
+++ b/examples/example3b_spi_tclasm/instructions.s.tcl
@@ -0,0 +1,142 @@
+### Relevant addresses:
+### * h140000 - h1401FF - SPI data transfer memory
+### * h140200 - h140201 - SPI bytes_to_output reg
+### * h140202 - h140203 - SPI bytes_to_receive reg
+### * h140204 - h140207 - SPI operating reg
+### * h1C0008 - h1C0009 - low bits of timer reg
+### * h100000 - h1009FF - VGA text memory
+### * h100A00 - h100A01 - VGA power-on register
+### * h1C0006 - h1C0007 - LED2 register
+
+### The bitstream binary itself is 135100 bytes big. We append our data
+### at the and of this binary file, so it can later be found at address
+### 135100 on the flash chip.
+
+set_sp h100000;                  # 2 16-bit instructions
+
+### power up flash ship
+## set bytes_to_output to 1
+const 1;                         # 1 16-bit instruction
+storew h140200;                  # 2 16-bit instructions
+## set bytes_to_receive to 0
+const 0;                         # 1 16-bit instruction
+storew h140202;                  # 2 16-bit instructions
+## release power-down SPI command
+const 0xAB;                      # 2 16-bit instructions
+storeb h140000;                  # 2 16-bit instructions
+## start SPI operation
+const 1;                         # 1 16-bit instruction
+storew h140204;                  # 2 16-bit instructions
+
+### wait for at least 3000 ns after command gets sent
+## reset the timer
+const 0;                         # 1 16-bit instruction
+storew h1C0008;                  # 2 16-bit instructions
+
+## loop until 45 ticks pass; 45 ticks is 3600 ns; additional 600ns is enough
+## for power-up command to be sent
+# there were 18 16-bit instructions up to this point, so loop address is 36
+loadwzx h1C0008;                 # 2 16-bit instructions
+const 45;                        # 1 16-bit instruction
+lt;                              # 1 16-bit instruction
+cond_jump 36;                    # 1 16-bit instruction
+
+### we'll transfer a total of 2400 bytes by making 5 transfers of 480 bytes;
+### our SPI peripheral is capable of transfering at most 511 bytes in one go
+## initialize transfers counter
+const 0;                         # 1 16-bit instruction
+storew h080000;                  # 2 16-bit instructions
+
+### transfers loop starts here, it'll execute 5 times
+# there were 26 16-bit instructions up to this point, so loop address is 52
+### read 480 bytes from SPI
+## set bytes_to_output to 5
+const 5;                         # 1 16-bit instruction
+storew h140200;                  # 2 16-bit instructions
+## set bytes_to_receive to 480
+const 480;                       # 2 16-bit instructions
+storew h140202;                  # 2 16-bit instructions
+## fast read SPI command
+const 0x0B;                      # 1 16-bit instruction
+storeb h140000;                  # 2 16-bit instructions
+## prepare address; 135100 is base address of our data inside flash memory
+const 135100;                    # 2 16-bit instructions
+## compute the offset of bytes, that have already been read
+loadwzx h080000;                 # 2 16-bit instructions
+const 480;                       # 2 16-bit instructions
+mul;                             # 1 16-bit instruction
+## also store the computed offset for later
+storew h080002;                  # 2 16-bit instructions
+## add the offset
+loadwzx h080002;                 # 2 16-bit instructions
+add;                             # 1 16-bit instruction
+## store the address in big endian
+store h080008;                   # 2 16-bit instructions
+load h080008;                    # 2 16-bit instructions
+const 256;                       # 2 16-bit instructions
+div;                             # 1 16-bit instruction
+storew h140002;                  # 2 16-bit instructions
+load h080008;                    # 2 16-bit instructions
+storeb h140003;                  # 2 16-bit instructions
+load h080008;                    # 2 16-bit instructions
+const 65536;                     # 2 16-bit instructions
+div;                             # 1 16-bit instruction
+storeb h140001;                  # 2 16-bit instructions
+## start SPI operation
+const 1;                         # 1 16-bit instruction
+storew h140204;                  # 2 16-bit instructions
+
+### force wait for operation completion
+const 0;                         # 1 16-bit instruction
+storew h140200;                  # 2 16-bit instructions
+
+### assume data to be ascii characters and print it to screen
+### initialize index to 0
+const 0;                         # 1 16-bit instruction
+storew h080004;                  # 2 16-bit instructions
+
+## print characters in a loop
+# there were 77 16-bit instructions up to this point, so loop address is 154
+## load current index value, get 2 copies of it, add offset to one copy
+loadwzx h080004
+loadwzx h080002
+add
+loadwzx h080004
+## load 4 bytes from SPI memory
+load+ h140000
+## write to VGA memory
+store+ h100000
+## increase index
+loadwzx h080004
+const 4
+add
+storew h080004
+## compare index to 479
+loadwzx h080004
+const 479
+lt
+cond_jump 154
+
+## increase transfers count
+loadwzx h080000
+const 1
+add
+storew h080000
+
+## switch LED2
+loadwzx h080000
+const 2
+rem
+storew h1C0006
+
+## if less than 5 transfers were done, continue with another one
+loadwzx h080000
+const 5
+lt
+cond_jump 52
+
+### after loops, start generating VGA output
+const -1
+store h100A00
+
+halt