text: /**
   * Marlin 3D Printer Firmware
   * Copyright (C) 2019 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
   *
   * Based on Sprinter and grbl.
   * Copyright (C) 2011 Camiel Gubbels / Erik van der Zalm
   *
   * This program is free software: you can redistribute it and/or modify
   * it under the terms of the GNU General Public License as published by
   * the Free Software Foundation, either version 3 of the License, or
   * (at your option) any later version.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program.  If not, see <http://www.gnu.org/licenses/>.
   *
   */
  
  // NOTE - the HAL version of the rrd device uses a generic ST7920 device.  See the
  // file u8g_dev_st7920_128x64_HAL.cpp for the HAL version.
  
  #include "../../inc/MarlinConfig.h"
  
  #if ENABLED(U8GLIB_ST7920) && !defined(U8G_HAL_LINKS) && !defined(__SAM3X8E__)
  
  #include "../../HAL/shared/Delay.h"
  
  #define ST7920_CLK_PIN  LCD_PINS_D4
  #define ST7920_DAT_PIN  LCD_PINS_ENABLE
  #define ST7920_CS_PIN   LCD_PINS_RS
  
  //#define PAGE_HEIGHT 8   //128 byte framebuffer
  #define PAGE_HEIGHT 16  //256 byte framebuffer
  //#define PAGE_HEIGHT 32  //512 byte framebuffer
  
  #define LCD_PIXEL_WIDTH 128
  #define LCD_PIXEL_HEIGHT 64
  
  #include <U8glib.h>
  
  // If you want you can define your own set of delays in Configuration.h
  //#define ST7920_DELAY_1 DELAY_NS(0)
  //#define ST7920_DELAY_2 DELAY_NS(0)
  //#define ST7920_DELAY_3 DELAY_NS(0)
  
  #if F_CPU >= 20000000
    #define CPU_ST7920_DELAY_1 DELAY_NS(0)
    #define CPU_ST7920_DELAY_2 DELAY_NS(0)
    #define CPU_ST7920_DELAY_3 DELAY_NS(50)
  #elif MB(3DRAG) || MB(K8200) || MB(K8400) || MB(SILVER_GATE)
    #define CPU_ST7920_DELAY_1 DELAY_NS(0)
    #define CPU_ST7920_DELAY_2 DELAY_NS(188)
    #define CPU_ST7920_DELAY_3 DELAY_NS(0)
  #elif MB(MINIRAMBO) || MB(EINSY_RAMBO) || MB(EINSY_RETRO)
    #define CPU_ST7920_DELAY_1 DELAY_NS(0)
    #define CPU_ST7920_DELAY_2 DELAY_NS(250)
    #define CPU_ST7920_DELAY_3 DELAY_NS(0)
  #elif MB(RAMBO)
    #define CPU_ST7920_DELAY_1 DELAY_NS(0)
    #define CPU_ST7920_DELAY_2 DELAY_NS(0)
    #define CPU_ST7920_DELAY_3 DELAY_NS(0)
  #elif MB(BQ_ZUM_MEGA_3D)
    #define CPU_ST7920_DELAY_1 DELAY_NS(0)
    #define CPU_ST7920_DELAY_2 DELAY_NS(0)
    #define CPU_ST7920_DELAY_3 DELAY_NS(189)
  #elif defined(ARDUINO_ARCH_STM32)
    #define CPU_ST7920_DELAY_1 DELAY_NS(300)
    #define CPU_ST7920_DELAY_2 DELAY_NS(40)
    #define CPU_ST7920_DELAY_3 DELAY_NS(340)
  #elif F_CPU == 16000000
    #define CPU_ST7920_DELAY_1 DELAY_NS(0)
    #define CPU_ST7920_DELAY_2 DELAY_NS(0)
    #define CPU_ST7920_DELAY_3 DELAY_NS(63)
  #else
    #error "No valid condition for delays in 'ultralcd_st7920_u8glib_rrd_AVR.h'"
  #endif
  
  void ST7920_SWSPI_SND_8BIT(uint8_t val);
  
  #if DOGM_SPI_DELAY_US > 0
    #define U8G_DELAY() DELAY_US(DOGM_SPI_DELAY_US)
  #else
    #define U8G_DELAY() DELAY_US(10)
  #endif
  
  #define ST7920_CS()              { WRITE(ST7920_CS_PIN,1); U8G_DELAY(); }
  #define ST7920_NCS()             { WRITE(ST7920_CS_PIN,0); }
  #define ST7920_SET_CMD()         { ST7920_SWSPI_SND_8BIT(0xF8); U8G_DELAY(); }
  #define ST7920_SET_DAT()         { ST7920_SWSPI_SND_8BIT(0xFA); U8G_DELAY(); }
  #define ST7920_WRITE_BYTE(a)     { ST7920_SWSPI_SND_8BIT((uint8_t)((a)&0xF0u)); ST7920_SWSPI_SND_8BIT((uint8_t)((a)<<4u)); U8G_DELAY(); }
  #define ST7920_WRITE_BYTES(p,l)  { for (uint8_t i = l + 1; --i;) { ST7920_SWSPI_SND_8BIT(*p&0xF0); ST7920_SWSPI_SND_8BIT(*p<<4); p++; } U8G_DELAY(); }
  
  #endif // U8GLIB_ST7920 && !U8G_HAL_LINKS && !__SAM3X8E__
  