【MCX-N947分享】+Flexio驱动8080 TFT_LCD

leo121_3006061

        今天主要学习flexio来驱动16bit mpu8080 接口的TFT_LCD并记录下来和大家分享我的学习过程,flexio可以实现很多功能，例如pwm，can，spi，模拟camera，可见功能强大，开始本次实验之前，首先回顾以下mcxn947芯片的诸多令人兴奋的新特性。
FeaturesCore Platform

• Arm® Cortex®-M33 @ 150 MHz (Dual core)
• DSP Accelerator (PowerQUAD, with Co-Processor interface)
• SmartDMA (co-processor for applications such as parallel camera interface and keypad scanning)
• eIQ® Neutron N1-16 Neural Processing Unit
• Power Line Communications (PLC) Controller
  

Memory

• Up to 2 MB (2 x 1MB Bank) on chip Flash
  
  • Supporting Flash Swap and Read While Write
    
• Cache Engine with 16 KB RAM
• Up to 512 KB RAM, configurable as up to 416 KB with ECC (support single bit correction two bits detection)
  
  • Up to 4x 8 KB ECC RAM can be retained down to VBAT mode
    
• FlexSPI with 16 KB cache supporting XIP, Octal/Quad SPI flash, HyperFlash, HyperRAM, Xccela memory types
  

Peripherals

• Analog
  
  • 4x 16bit ADC (Single Ended) or 2x16bit (Differential)
    
    • Up to 2 Msps in 16bit mode and 3.3 Msps in 12bit mode
      
  • Integrated temperature sensor connected per ADC
  • Three high-speed comparators with 17 input pins and 8-bit DAC as internal reference
    
    • 2x CMP is functional down to Deep Power Down mode
      
  • Two 12-bit DAC with sample rates of up to 1.0 MSample/sec
  • One 14-bit DAC with sample rates of up to 10 MSample/sec
  • Three OpAmps can be configured to:
    
    • Programmable Gain Amplifier
    • Differential Amplifier
    • Instrument Amplifier
    • Transconductance Amplifier
      
  • Highly accurate VREF ±0.15 % and 15 ppm/deg C drift
    
• Timers
  
  • Five 32-bit standard general-purpose asynchronous timers/counters, which support up to four capture inputs and four compare outputs, PWM mode and external count input. Specific timer events can be selected to generate DMA requests.
  • SCTimer/PWM
  • LPTimer
  • Frequency measurement timer
  • Multi-Rate Timer
  • Windowed Watchdog Timer
  • RTC with calendar
  • Micro Timer
  • OS Event Timer
    
• Communication interfaces
  
  • USB high-speed (Host/Device) with on-chip HS PHY
  • USB full-speed (Host/Device) with on-chip FS PHY, USB Device
  • uSDHC (Micro SD High Speed Card Interface)
  • 10x LP Flexcomms each supporting SPI, I2C, UART
  • 2x FlexCAN with FD, 2x I3Cs, 2x SAI
  • 1x Ethernet with QoS
  • 1x FlexIO programmable as a variety of serial and parallel interfaces, including, but not limited to Display Driver and camera interface
  • 2x EVM Smart Card Interfaces
  • Programmable Logic Unit (PLU)
    
• Motor Control Subsystem
  
  • 2x eFlexPWM each with 4 sub-modules, providing 12 PWM outputs
  • 2x Quadrature Encoder/Decoder (ENC)
  • 1x Event Generator (AND/OR/INVERT) module support up to 8 output trigger
  • SINC Filter Module (3rd order, 5ch, break signals connections to PWM)
    

Security


再看一下架构图，图形是工程师语言，上边的千言万语汇集成一张图

开始今天的实验过程
【软件：】
OS：windows11
Dev tools：MDK Keil
sdk: mcuxpresso sdk 2.14
【硬件：】
mcxn947_brk开发板
HX8357A tft_lcd
杜邦线
dap link
【设置】
从原理图中可以看出点屏所需要的pin设置

由于屏的转接板不能和这个开发板很好的契合，所以二者之间需要用大量的杜邦线来连接。

【实验过程】
1. 为了快速开发，直接使用官方的例程，从sdk中打开lvgl_demo_widgets，
也可用drivers_example/flexio/mculcd来修改

先了解一下flexio驱动lcd的过程，1.先设置好flexio，并配置好pin =》 2. 初始化flexio及pin=》 3.设置lcd的属性=》4.初始化lcd。
由于我用的lcd是HX8357A,翻阅手册发现和例程里使用的ST7796s的寄存器完全不同，需要重新构造初始化，开窗函数等,过程费时
2.直接用st7796s修改初lcd始化参数。


附上初始化代码，如下

1. 0x01, 0xFF,0x00,  // Command page 0
   
2.         0x01, 0x72,0xF6,  // SUB_SEL=0xF6
   
3.         // Power saving for HX8357-A
   
4.         0x01, 0xFF,0x00,  // Command page 0
   
5.         0x01, 0xF2,0x00,  // GENON=0x00
   
6.         0x01, 0xE4,0x00,  // EQVCI_M1=0x00
   
7.         0x01, 0xE5,0x1C,  // EQGND_M1=0x1C
   
8.         0x01, 0xE6,0x00,  // EQVCI_M0=0x1C
   
9.         0x01, 0xE7,0x1C,  // EQGND_M0=0x1C
   
10.         0x01, 0xEE,0x42,  // For GRAM read/write speed
    
11.         0x01, 0xEF,0xDB,  // For GRAM read/write speed
    
12.          0x01, 0x2E,0x98,  //For Gate timing, prevent the display abnormal in RGB I/F
    
13.         // Gamma
    
14.         0x01, 0x40,0x00,  
    
15.         0x01, 0x41,0x2E,  
    
16.         0x01, 0x42,0x2D,  
    
17.         0x01, 0x43,0x3F,  
    
18.         0x01, 0x44,0x3F,  
    
19.         0x01, 0x45,0x3F,  
    
20.         0x01, 0x46,0x2C,  
    
21.         0x01, 0x47,0x7F,  
    
22.         0x01, 0x48,0x07,  
    
23.         0x01, 0x49,0x05,  
    
24.         0x01, 0x4A,0x08,  
    
25.         0x01, 0x4B,0x13,  
    
26.         0x01, 0x4C,0x1E,  
    
27.         0x01, 0x50,0x00,  
    
28.         0x01, 0x51,0x00,  
    
29.         0x01, 0x52,0x00,  
    
30.         0x01, 0x53,0x12,  
    
31.         0x01, 0x54,0x11,  
    
32.         0x01, 0x55,0x3F,  
    
33.         0x01, 0x56,0x00,  
    
34.         0x01, 0x57,0x53,  
    
35.         0x01, 0x58,0x01,  
    
36.         0x01, 0x59,0x0C,  
    
37.         0x01, 0x5A,0x17,  
    
38.         0x01, 0x5B,0x1A,  
    
39.         0x01, 0x5C,0x18,  
    
40.         0x01, 0x5D,0xC3,  
    
41.         
    
42.         
    
43.         
    
44.         // Set GRAM area 320x480
    
45.         0x01, 0x02,0x00,  
    
46.         0x01, 0x03,0x00,  
    
47.         0x01, 0x04,0x01,  
    
48.         0x01, 0x05,0x3F,  
    
49.         0x01, 0x06,0x00,  
    
50.         0x01, 0x07,0x00,  
    
51.         0x01, 0x08,0x00,  
    
52.         0x01, 0x09,0xDF, //0xEF 320x240
    
53.          
    
54.         0x01, 0x24,0x22,  // Set VCOMH voltage, VHH=0x64
    
55.         0x01, 0x25,0x64,  // Set VCOML voltage, VML=0x71
    
56.         0x01, 0x23,0x90,  // Set VCOM offset, VMF=0x52
    
57.         0x01, 0x1B,0x0E,  // Set VERG1 voltage, VRH[5:0]=0x1E
    
58.         0x01, 0x1D,0x11,  // FS0[1:0]=01, Set the operating frequency of the step-up circuit 1
    
59.         // Power on Setting
    
60.         0x01, 0x19,0x01,  // OSC_EN=1, Start to Oscillate
    
61.         0x01, 0x1C,0x03,  // AP=011
    
62.         0x01, 0x01,0x00,  // Normal display(Exit Deep standby mode)
    
63.         0x01, 0x1F,0x80,  // Exit standby mode and Step-up circuit 1 enable
    
64.         // GAS_EN=1, VCOMG=0, PON=0, DK=0, XDK=0, DDVDH_TRI=0, STB=0
    
65.          
    
66.         0x01, 0x1F,0x90,  // Step-up circuit 2 enable
    
67.         // GAS_EN=1, VCOMG=0, PON=1, DK=0, XDK=0, DDVDH_TRI=0, STB=0
    
68.          
    
69.         0x01, 0x1F,0xD4,  
    
70.         // GAS_EN=1, VCOMG=1, PON=1, DK=0, XDK=1, DDVDH_TRI=0, STB=0
    
71.          
    
72.         // Display ON Setting
    
73.         0x01, 0x28,0x08,  // GON=0, DTE=0, D[1:0]=01
    
74.          
    
75.         0x01, 0x28,0x38,  // GON=1, DTE=1, D[1:0]=10
    
76.          
    
77.         0x01, 0x28,0x3C,  // GON=1, DTE=1, D[1:0]=11
    
78.          
    
79. 
    
80.          0x01, 0x17,0x05,  // 16-bit/pixel         
    
81.          
    
82.          //HX8357-A_Update_GRAM
    
83.          // Set GRAM start address (0x0000, 0x0000)
    
84.          0x01,0xFF,0x00, ////Select Command Page 0
    
85.          // If command page not change, the RFFh can remove
    
86.          0x01,0x80,0x00, // Set CAC=0x0000
    
87.    0x01,0x81,0x00,
    
88.          0x01,0x82,0x00, // Set RAC=0x0000
    
89.    0x01,0x83,0x00,
    
90.    0x00,0x22, //Write GRAM command
    
91.          

复制代码

修改开窗函数

经过这一阵子的研究，重新画板子，终于成功了，补发几张图完善本贴。





表示已经成功了。
lvgl_demo_widgets.zip (116.64 KB, 下载次数: 1)

2024-3-10 15:15 上传

点击文件名下载附件 st7796s.zip (6.4 KB, 下载次数: 0)

2024-3-10 15:17 上传

点击文件名下载附件
【小节】通过本次实验，初步了解flexio的强大功能，可以实现I2C，SPI，QSPI，Camera，mcu8080/68000,RGB interface的tftlcd的驱动，lin都很轻松的实现。

阅读全文