| Line 2... |
Line 2... |
//
|
//
|
// Filename: lloled.v
|
// Filename: lloled.v
|
//
|
//
|
// Project: OpenArty, an entirely open SoC based upon the Arty platform
|
// Project: OpenArty, an entirely open SoC based upon the Arty platform
|
//
|
//
|
// Purpose:
|
// Purpose: This is a low-level SPI output (not input) controller
|
|
// designed to command interactions between an upper level
|
|
// controller and a PModOLEDrgb. As a result, this is a one-bit
|
|
// (traditional, not quad) SPI controller, it has no MISO input bits,
|
|
// and it also controls a DCN bits (output data at active high, vs
|
|
// output control at active low).
|
|
//
|
|
// This particular implementation was taken from a low-level QSPI
|
|
// controller. For those who wish to compare, the low-level QSPI
|
|
// controller is very similar to the low-level EQSPI controller that is
|
|
// also a part of the OpenArty project.
|
|
//
|
|
// Interfacing with the controller works as follows: If the controller
|
|
// is idle, set the values you wish to send and strobe the i_wr bit.
|
|
// Once the last bit has been committed to the interface, but before it
|
|
// closes the connection by setting CS_N high, it will check the i_wr bit
|
|
// again. If that bit is high, the busy bit will be dropped for one
|
|
// cycle, new data will be accepted, and the controller will continue
|
|
// with the new(er) data as though it was still part of the last
|
|
// transmission (without lowering cs_n).
|
//
|
//
|
// Creator: Dan Gisselquist, Ph.D.
|
// Creator: Dan Gisselquist, Ph.D.
|
// Gisselquist Technology, LLC
|
// Gisselquist Technology, LLC
|
//
|
//
|
////////////////////////////////////////////////////////////////////////////////
|
////////////////////////////////////////////////////////////////////////////////
|
| Line 37... |
Line 56... |
`define OLED_START 3'h1
|
`define OLED_START 3'h1
|
`define OLED_BITS 3'h2
|
`define OLED_BITS 3'h2
|
`define OLED_READY 3'h3
|
`define OLED_READY 3'h3
|
`define OLED_STOP 3'h4
|
`define OLED_STOP 3'h4
|
`define OLED_STOP_B 3'h5
|
`define OLED_STOP_B 3'h5
|
|
`define OLED_STOP_C 3'h6
|
|
|
// Modes
|
// Modes
|
`define OLED_MOD_SPI 2'b00
|
`define OLED_MOD_SPI 2'b00
|
`define OLED_MOD_QOUT 2'b10
|
`define OLED_MOD_QOUT 2'b10
|
`define OLED_MOD_QIN 2'b11
|
`define OLED_MOD_QIN 2'b11
|
| Line 155... |
Line 175... |
o_cs_n <= 1'b0;
|
o_cs_n <= 1'b0;
|
o_busy <= 1'b1;
|
o_busy <= 1'b1;
|
o_mosi <= r_word[31];
|
o_mosi <= r_word[31];
|
end else if (~last_counter)
|
end else if (~last_counter)
|
begin
|
begin
|
o_busy <= (pre_last_counter)&&(o_sck)
|
o_busy <= (!pre_last_counter)||(!o_sck)
|
&&((state != `OLED_READY)||(~i_wr));
|
||(state != `OLED_READY)||(~i_wr);
|
end else if (~o_sck)
|
end else if (~o_sck)
|
begin
|
begin
|
o_sck <= 1'b1;
|
o_sck <= 1'b1;
|
o_busy <= 1'b1;
|
o_busy <= 1'b1;
|
end else if (state == `OLED_BITS)
|
end else if (state == `OLED_BITS)
|
| Line 203... |
Line 223... |
end else if (state == `OLED_STOP)
|
end else if (state == `OLED_STOP)
|
begin
|
begin
|
o_sck <= 1'b1; // Stop the clock
|
o_sck <= 1'b1; // Stop the clock
|
o_busy <= 1'b1; // Still busy till port is clear
|
o_busy <= 1'b1; // Still busy till port is clear
|
state <= `OLED_STOP_B;
|
state <= `OLED_STOP_B;
|
end else // if (state == `OLED_STOP_B)
|
end else if (state == `OLED_STOP_B)
|
begin
|
begin
|
o_cs_n <= 1'b1; // Deselect CS
|
o_cs_n <= 1'b1; // Deselect CS
|
o_sck <= 1'b1;
|
o_sck <= 1'b1;
|
// Do I need this????
|
// Do I need this????
|
// spi_len <= 3; // Minimum CS high time before next cmd
|
// spi_len <= 3; // Minimum CS high time before next cmd
|
|
state <= `OLED_STOP_C;
|
|
o_mosi <= 1'b1;
|
|
o_busy <= 1'b1;
|
|
end else // if (state == `OLED_STOP_C)
|
|
begin
|
|
// Keep us in idle for at least a full clock period.
|
|
o_cs_n <= 1'b1; // Deselect CS
|
|
o_sck <= 1'b1;
|
|
// Do I need this????
|
|
// spi_len <= 3; // Minimum CS high time before next cmd
|
state <= `OLED_IDLE;
|
state <= `OLED_IDLE;
|
o_mosi <= 1'b1;
|
o_mosi <= 1'b1;
|
o_busy <= 1'b1;
|
o_busy <= 1'b1;
|
end
|
end
|
/*
|
/*
|
