`timescale 1ns / 1ps//////////////////////////////////////////////////////////////////////////////////// Engineer: Hiram Lee yangli0534@gmail.com//// Create Date: 18:33:26 05/06/2012// Design Name: lcd test via Picoblaze on Spartan 3e start kit// Module Name: lcd// Project Name: lcd test// Target Devices: x3cs500e fp320// Tool versions: ise 10.1.03// Description: Print "PicoBlaze " on the LCD// Reference Design: Xilinx PicoBlaze controlling the two channel programmable// amplifier type LTC6912-1 and two channel A/D converter type LTC1407A-1 from// Linear Technology.// Dependencies://// Revision:// Revision 0.01 - File Created// Additional Comments:////////////////////////////////////////////////////////////////////////////////////module lcd ( input wire clk, reset, output wire lcd_rs, lcd_rw, lcd_e, output wire strataflash_oe, strataflash_ce, strataflash_we, platformflash_oe, inout wire [7:4] lcd_d ); wire [9:0] address; wire [17:0] instruction; wire [7:0] in_port, out_port, port_id; wire write_strobe, read_strobe;//kcpsm3 and instruction memorykcpsm3 unit_proc( .address(address), .instruction(instruction), .port_id(port_id), .write_strobe(write_strobe), .out_port(out_port), .read_strobe(read_strobe), .in_port(in_port), .interrupt(1'b0), .interrupt_ack(), .reset(reset), .clk(clk)) ; program unit_rom(.address(address), .instruction(instruction), .clk(clk)); //---------------------------------------------------------------------------------------------------------------------------------- // Input interface //---------------------------------------------------------------------------------------------------------------------------------- reg in_port_data; always @(posedge clk) if(read_strobe==1'b1 && port_id[1] == 1'b1) in_port_data<=lcd_d & 8'hf0;elsein_port_data <= 8'hzz; assign in_port = in_port_data; // ---------------------------------------------------------------------------------------------------------------------------------- // Output interface //--------------------------------------------------------------------------------------------------------------------------------- //disable the signal that share the same port assign strataflash_oe = 1'b1, strataflash_ce = 1'b1, strataflash_we = 1'b1, platformflash_oe = 1'b0; // read and write control reg lcd_rw_control, lcd_drive, lcd_rs_reg, lcd_e_reg; reg [7:4] lcd_out_data; always @(posedge clk) if(write_strobe==1'b1 && port_id[6] == 1'b1) begin lcd_out_data <= out_port[7:4]; lcd_drive <= out_port[3]; lcd_rs_reg <= out_port[2]; lcd_rw_control <= out_port[1]; lcd_e_reg <= out_port[0]; end assign lcd_rs = lcd_rs_reg, lcd_e = lcd_e_reg; //---------------------------------------------------------------------------------------------------------------------------------- // LCD interface //---------------------------------------------------------------------------------------------------------------------------------- assign lcd_rw = lcd_rw_control & lcd_drive; assign lcd_d = (lcd_rw_control==1'b0 && lcd_drive==1'b1) ? lcd_out_data :4'bZZZZ; endmodule

其中PicoBlaze的汇编程序如下：

;fuction: print'PicoBlaze'on the screen ;LCDinterfaceports ; ;The master enable signalisnot used by the LCD display itself ;but may be required to confirm that LCD communicationisactive. ;Thisisrequired on the Spartan-3E Starter Kitifthe StrataFLASH ;isused because it shares the same data pins and conflicts must be avoided. ; CONSTANT LCD_output_port, 40 ;LCD character module output data and control CONSTANT LCD_E, 01 ; active High Enable E - bit0 CONSTANT LCD_RW, 02 ; Read=1 Write=0 RW - bit1 CONSTANT LCD_RS, 04 ; Instruction=0 Data=1 RS - bit2 CONSTANT LCD_drive, 08 ; Master enable (active High) - bit3 CONSTANT LCD_DB4, 10 ; 4-bit Data DB4 - bit4 CONSTANT LCD_DB5, 20 ;interfaceData DB5 - bit5 CONSTANT LCD_DB6, 40 ; Data DB6 - bit6 CONSTANT LCD_DB7, 80 ; Data DB7 - bit7 ; ; CONSTANT LCD_input_port, 02 ;LCD character module input data CONSTANT LCD_read_spare0, 01 ; Spare bits - bit0 CONSTANT LCD_read_spare1, 02 ; are zero - bit1 CONSTANT LCD_read_spare2, 04 ; - bit2 CONSTANT LCD_read_spare3, 08 ; - bit3 CONSTANT LCD_read_DB4, 10 ; 4-bit Data DB4 - bit4 CONSTANT LCD_read_DB5, 20 ;interfaceData DB5 - bit5 CONSTANT LCD_read_DB6, 40 ; Data DB6 - bit6 CONSTANT LCD_read_DB7, 80 ; Data DB7 - bit7 ; ; ;Constant to define a software delay of 1us. This must be adjusted to reflect the ;clock applied to KCPSM3. Every instruction executesin2 clock cycles making the ;calculation highly predictable. The'6'inthe following equation even allowsfor;'CALL delay_1us'instructioninthe initiating code. ; ; delay_1us_constant = (clock_rate - 6)/4 Where'clock_rate'isinMHz ; ;Example: For a 50MHz clock the constantvalueis(10-6)/4 = 11 (0B Hex). ;For clock rates below 10MHz thevalueof 1 must be used and the operation will ;become lower than intended. ; CONSTANT delay_1us_constant, 0B ; ; ; ;ASCII table ; CONSTANT character_a, 61 CONSTANT character_b, 62 CONSTANT character_c, 63 CONSTANT character_d, 64 CONSTANT character_e, 65 CONSTANT character_f, 66 CONSTANT character_g, 67 CONSTANT character_h, 68 CONSTANT character_i, 69 CONSTANT character_j, 6A CONSTANT character_k, 6B CONSTANT character_l, 6C CONSTANT character_m, 6D CONSTANT character_n, 6E CONSTANT character_o, 6F CONSTANT character_p, 70 CONSTANT character_q, 71 CONSTANT character_r, 72 CONSTANT character_s, 73 CONSTANT character_t, 74 CONSTANT character_u, 75 CONSTANT character_v, 76 CONSTANT character_w, 77 CONSTANT character_x, 78 CONSTANT character_y, 79 CONSTANT character_z, 7A CONSTANT character_A, 41 CONSTANT character_B, 42 CONSTANT character_C, 43 CONSTANT character_D, 44 CONSTANT character_E, 45 CONSTANT character_F, 46 CONSTANT character_G, 47 CONSTANT character_H, 48 CONSTANT character_I, 49 CONSTANT character_J, 4A CONSTANT character_K, 4B CONSTANT character_L, 4C CONSTANT character_M, 4D CONSTANT character_N, 4E CONSTANT character_O, 4F CONSTANT character_P, 50 CONSTANT character_Q, 51 CONSTANT character_R, 52 CONSTANT character_S, 53 CONSTANT character_T, 54 CONSTANT character_U, 55 CONSTANT character_V, 56 CONSTANT character_W, 57 CONSTANT character_X, 58 CONSTANT character_Y, 59 CONSTANT character_Z, 5A CONSTANT character_0, 30 CONSTANT character_1, 31 CONSTANT character_2, 32 CONSTANT character_3, 33 CONSTANT character_4, 34 CONSTANT character_5, 35 CONSTANT character_6, 36 CONSTANT character_7, 37 CONSTANT character_8, 38 CONSTANT character_9, 39 CONSTANT character_colon, 3A CONSTANT character_stop, 2E CONSTANT character_semi_colon, 3B CONSTANT character_minus, 2D CONSTANT character_divide, 2F ;'/'CONSTANT character_plus, 2B CONSTANT character_comma, 2C CONSTANT character_less_than, 3C CONSTANT character_greater_than, 3E CONSTANT character_equals, 3D CONSTANT character_space, 20 CONSTANT character_CR, 0D ;carriagereturnCONSTANT character_question, 3F ;'?'CONSTANT character_dollar, 24 CONSTANT character_exclaim, 21 ;'!'CONSTANT character_BS, 08 ;Back Space command character ; ;routine ;initializaion ;print cold_start: call LCD_reset ;initialise LCD display ;Write welcome message to LCD display ; LOAD s5, 10 ;Line 1 position 0 CALL LCD_cursor CALL disp_PicoBlaze ;Display'PicoBlaze Inside'stop:load s0,s0 ; jump stop ;************************************************************************************** ;LCD text messages ;************************************************************************************** ; ; ;Display'PicoBlaze'on LCD at current cursor position ; ; disp_PicoBlaze: LOAD s5, character_P CALL LCD_write_data LOAD s5, character_i CALL LCD_write_data LOAD s5, character_c CALL LCD_write_data LOAD s5, character_o CALL LCD_write_data LOAD s5, character_B CALL LCD_write_data LOAD s5, character_l CALL LCD_write_data LOAD s5, character_a CALL LCD_write_data LOAD s5, character_z CALL LCD_write_data LOAD s5, character_e CALL LCD_write_data RETURN ; ;************************************************************************************** ;Software delay routines ;************************************************************************************** ; ; ; ;Delay of 1us. ; ;Constantvaluedefines reflects the clock applied to KCPSM3. Every instruction ;executesin2 clock cycles making the calculation highly predictable. The'6'in;the following equation even allowsfor'CALL delay_1us'instructioninthe initiating code. ; ; delay_1us_constant = (clock_rate - 6)/4 Where'clock_rate'isinMHz ; ;Registers used s0 ; delay_1us: LOAD s0, delay_1us_constant wait_1us: SUB s0, 01 JUMP NZ, wait_1us RETURN ; ;Delay of 40us. ; ;Registers used s0, s1 ; delay_40us: LOAD s1, 28 ;40 x 1us = 40us wait_40us: CALL delay_1us SUB s1, 01 JUMP NZ, wait_40us RETURN ; ; ;Delay of 1ms. ; ;Registers used s0, s1, s2 ; delay_1ms: LOAD s2, 19 ;25 x 40us = 1ms wait_1ms: CALL delay_40us SUB s2, 01 JUMP NZ, wait_1ms RETURN ; ;Delay of 20ms. ; ;Delay of 20ms used during initialisation. ; ;Registers used s0, s1, s2, s3 ; delay_20ms: LOAD s3, 14 ;20 x 1ms = 20ms wait_20ms: CALL delay_1ms SUB s3, 01 JUMP NZ, wait_20ms RETURN ; ;Delay of approximately 1 second. ; ;Registers used s0, s1, s2, s3, s4 ; delay_1s: LOAD s4, 32 ;50 x 20ms = 1000ms wait_1s: CALL delay_20ms SUB s4, 01 JUMP NZ, wait_1s RETURN ; ; ; ;************************************************************************************** ;LCD Character Module Routines ;************************************************************************************** ; ;LCD moduleisa 16 character by 2 line display but all displays are very similar ;The 4-wire datainterfacewill be used (DB4 to DB7). ; ;The LCD modules are relatively slow and software delay loops are used to slow down ;KCPSM3 adequatelyforthe LCD to communicate. The delay routines are providedin;a different section (see aboveinthiscase). ; ; ;Pulse LCD enable signal'E'highforgreater than 230ns (1usisused). ; ;Register s4 should define the current state of the LCD output port. ; ;Registers used s0, s4 ; LCD_pulse_E: XOR s4, LCD_E ;E=1 OUTPUT s4, LCD_output_port CALL delay_1us XOR s4, LCD_E ;E=0 OUTPUT s4, LCD_output_port RETURN ; ;Write 4-bit instruction to LCD display. ; ;The 4-bit instruction should be providedinthe upper 4-bits of register s4. ;Note thatthisroutine does not release the master enable butasitisonly ;used during initialisation andaspart of the 8-bit instruction write it ;should be acceptable. ; ;Registers used s4 ; LCD_write_inst4: AND s4, F8 ;Enable=1 RS=0 Instruction, RW=0 Write, E=0 OUTPUT s4, LCD_output_port ;set up RS and RW >40ns before enable pulse CALL LCD_pulse_E RETURN ; ; ;Write 8-bit instruction to LCD display. ; ;The 8-bit instruction should be providedinregister s5. ;Instructions are writtenusingthe following sequence ; Upper nibble ; wait >1us ; Lower nibble ; wait >40us ; ;Registers used s0, s1, s4, s5 ; LCD_write_inst8: LOAD s4, s5 AND s4, F0 ;Enable=0 RS=0 Instruction, RW=0 Write, E=0 OR s4, LCD_drive ;Enable=1 CALL LCD_write_inst4 ;write upper nibble CALL delay_1us ;wait >1us LOAD s4, s5 ;select lower nibble with SL1 s4 ;Enable=1 SL0 s4 ;RS=0 Instruction SL0 s4 ;RW=0 Write SL0 s4 ;E=0 CALL LCD_write_inst4 ;write lower nibble CALL delay_40us ;wait >40us LOAD s4, F0 ;Enable=0 RS=0 Instruction, RW=0 Write, E=0 OUTPUT s4, LCD_output_port ;Release master enable RETURN ; ; ; ;Write 8-bit data to LCD display. ; ;The 8-bit data should be providedinregister s5. ;Data bytes are writtenusingthe following sequence ; Upper nibble ; wait >1us ; Lower nibble ; wait >40us ; ;Registers used s0, s1, s4, s5 ; LCD_write_data: LOAD s4, s5 AND s4, F0 ;Enable=0 RS=0 Instruction, RW=0 Write, E=0 OR s4, 0C ;Enable=1 RS=1 Data, RW=0 Write, E=0 OUTPUT s4, LCD_output_port ;set up RS and RW >40ns before enable pulse CALL LCD_pulse_E ;write upper nibble CALL delay_1us ;wait >1us LOAD s4, s5 ;select lower nibble with SL1 s4 ;Enable=1 SL1 s4 ;RS=1 Data SL0 s4 ;RW=0 Write SL0 s4 ;E=0 OUTPUT s4, LCD_output_port ;set up RS and RW >40ns before enable pulse CALL LCD_pulse_E ;write lower nibble CALL delay_40us ;wait >40us LOAD s4, F0 ;Enable=0 RS=0 Instruction, RW=0 Write, E=0 OUTPUT s4, LCD_output_port ;Release master enable RETURN ; ; ; ; ;Read 8-bit data from LCD display. ; ;The 8-bit data will be read from the current LCD memory address ;and will be returnedinregister s5. ;Itisadvisable to set the LCD address (cursor position) before ;usingthe data readforthe first time otherwise the display may ;generate invalid data on the first read. ; ;Data bytes are readusingthe following sequence ; Upper nibble ; wait >1us ; Lower nibble ; wait >40us ; ;Registers used s0, s1, s4, s5 ; LCD_read_data8: LOAD s4, 0E ;Enable=1 RS=1 Data, RW=1 Read, E=0 OUTPUT s4, LCD_output_port ;set up RS and RW >40ns before enable pulse XOR s4, LCD_E ;E=1 OUTPUT s4, LCD_output_port CALL delay_1us ;wait >260ns to access data INPUT s5, LCD_input_port ;read upper nibble XOR s4, LCD_E ;E=0 OUTPUT s4, LCD_output_port CALL delay_1us ;wait >1us XOR s4, LCD_E ;E=1 OUTPUT s4, LCD_output_port CALL delay_1us ;wait >260ns to access data INPUT s0, LCD_input_port ;read lower nibble XOR s4, LCD_E ;E=0 OUTPUT s4, LCD_output_port AND s5, F0 ;merge upper and lower nibbles SR0 s0 SR0 s0 SR0 s0 SR0 s0 OR s5, s0 LOAD s4, 04 ;Enable=0 RS=1 Data, RW=0 Write, E=0 OUTPUT s4, LCD_output_port ;Stop reading 5V device and release master enable CALL delay_40us ;wait >40us RETURN ; ; ;Reset and initialise display to communicateusing4-bit data mode ;Includes routine to clear the display. ; ;Requires the 4-bit instructions 3,3,3,2 to be sent with suitable delays ;following by the 8-bit instructions to set up the display. ; ; 28 ='001'Function set,'0'4-bit mode,'1'2-line,'0'5x7 dot matrix,'xx'; 06 ='000001'Entry mode,'1'increment,'0'no display shift ; 0C ='00001'Display control,'1'display on,'0'cursor off,'0'cursor blink off ; 01 ='00000001'Display clear ; ;Registers used s0, s1, s2, s3, s4 ; LCD_reset: CALL delay_20ms ;wait more that 15msfordisplay to be ready LOAD s4, 30 CALL LCD_write_inst4 ;send'3'CALL delay_20ms ;wait >4.1ms CALL LCD_write_inst4 ;send'3'CALL delay_1ms ;wait >100us CALL LCD_write_inst4 ;send'3'CALL delay_40us ;wait >40us LOAD s4, 20 CALL LCD_write_inst4 ;send'2'CALL delay_40us ;wait >40us LOAD s5, 28 ;Function set CALL LCD_write_inst8 LOAD s5, 06 ;Entry mode CALL LCD_write_inst8 LOAD s5, 0C ;Display control CALL LCD_write_inst8 LCD_clear: LOAD s5, 01 ;Display clear CALL LCD_write_inst8 CALL delay_1ms ;wait >1.64msfordisplay to clear CALL delay_1ms RETURN ; ;Position the cursor readyforcharacters to be written. ;The displayisformed of 2 lines of 16 characters and each ;position has a corresponding addressasindicated below. ; ; Character position ; 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 ; ; Line 1 - 80 81 82 83 84 85 86 87 88 89 8A 8B 8C 8D 8E 8F ; Line 2 - C0 C1 C2 C3 C4 C5 C6 C7 C8 C9 CA CB CC CD CE CF ; ;This routine will set the cursor positionusingthevalueprovided ;inregister s5. The upper nibble will define the line and the lower ;nibble the character position on the line. ; Example s5 = 2B will position the cursor on line 2 position 11 ; ;Registers used s0, s1, s2, s3, s4 ; LCD_cursor: TEST s5, 10 ;testforline 1 JUMP Z, set_line2 AND s5, 0F ;make addressinrange 80 to 8Fforline 1 OR s5, 80 CALL LCD_write_inst8 ;instruction write to set cursor RETURN set_line2: AND s5, 0F ;make addressinrange C0 to CFforline 2 OR s5, C0 CALL LCD_write_inst8 ;instruction write to set cursor RETURN ; ;

1 Thessalonians 5:16-18“Rejoice always, pray continually, give thanks in all circumstances; for this is God’s will for you in Christ Jesus