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diff --git a/Marlin/src/HAL/AVR/HAL_SPI.cpp b/Marlin/src/HAL/AVR/HAL_SPI.cpp
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+++ b/Marlin/src/HAL/AVR/HAL_SPI.cpp
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+/**
+ * Marlin 3D Printer Firmware
+ * Copyright (c) 2020 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 <https://www.gnu.org/licenses/>.
+ *
+ */
+
+/**
+ * Adapted from Arduino Sd2Card Library
+ * Copyright (c) 2009 by William Greiman
+ */
+
+/**
+ * HAL for AVR - SPI functions
+ */
+
+#ifdef __AVR__
+
+#include "../../inc/MarlinConfig.h"
+
+void spiBegin() {
+  OUT_WRITE(SD_SS_PIN, HIGH);
+  SET_OUTPUT(SD_SCK_PIN);
+  SET_INPUT(SD_MISO_PIN);
+  SET_OUTPUT(SD_MOSI_PIN);
+
+  #if DISABLED(SOFTWARE_SPI)
+    // SS must be in output mode even it is not chip select
+    //SET_OUTPUT(SD_SS_PIN);
+    // set SS high - may be chip select for another SPI device
+    //#if SET_SPI_SS_HIGH
+      //WRITE(SD_SS_PIN, HIGH);
+    //#endif
+    // set a default rate
+    spiInit(1);
+  #endif
+}
+
+#if NONE(SOFTWARE_SPI, FORCE_SOFT_SPI)
+
+  // ------------------------
+  // Hardware SPI
+  // ------------------------
+
+  // make sure SPCR rate is in expected bits
+  #if (SPR0 != 0 || SPR1 != 1)
+    #error "unexpected SPCR bits"
+  #endif
+
+  /**
+   * Initialize hardware SPI
+   * Set SCK rate to F_CPU/pow(2, 1 + spiRate) for spiRate [0,6]
+   */
+  void spiInit(uint8_t spiRate) {
+    // See avr processor documentation
+    CBI(
+      #ifdef PRR
+        PRR
+      #elif defined(PRR0)
+        PRR0
+      #endif
+        , PRSPI);
+
+    SPCR = _BV(SPE) | _BV(MSTR) | (spiRate >> 1);
+    SPSR = spiRate & 1 || spiRate == 6 ? 0 : _BV(SPI2X);
+  }
+
+  /** SPI receive a byte */
+  uint8_t spiRec() {
+    SPDR = 0xFF;
+    while (!TEST(SPSR, SPIF)) { /* Intentionally left empty */ }
+    return SPDR;
+  }
+
+  /** SPI read data  */
+  void spiRead(uint8_t* buf, uint16_t nbyte) {
+    if (nbyte-- == 0) return;
+    SPDR = 0xFF;
+    for (uint16_t i = 0; i < nbyte; i++) {
+      while (!TEST(SPSR, SPIF)) { /* Intentionally left empty */ }
+      buf[i] = SPDR;
+      SPDR = 0xFF;
+    }
+    while (!TEST(SPSR, SPIF)) { /* Intentionally left empty */ }
+    buf[nbyte] = SPDR;
+  }
+
+  /** SPI send a byte */
+  void spiSend(uint8_t b) {
+    SPDR = b;
+    while (!TEST(SPSR, SPIF)) { /* Intentionally left empty */ }
+  }
+
+  /** SPI send block  */
+  void spiSendBlock(uint8_t token, const uint8_t* buf) {
+    SPDR = token;
+    for (uint16_t i = 0; i < 512; i += 2) {
+      while (!TEST(SPSR, SPIF)) { /* Intentionally left empty */ }
+      SPDR = buf[i];
+      while (!TEST(SPSR, SPIF)) { /* Intentionally left empty */ }
+      SPDR = buf[i + 1];
+    }
+    while (!TEST(SPSR, SPIF)) { /* Intentionally left empty */ }
+  }
+
+
+  /** begin spi transaction */
+  void spiBeginTransaction(uint32_t spiClock, uint8_t bitOrder, uint8_t dataMode) {
+    // Based on Arduino SPI library
+    // Clock settings are defined as follows. Note that this shows SPI2X
+    // inverted, so the bits form increasing numbers. Also note that
+    // fosc/64 appears twice
+    // SPR1 SPR0 ~SPI2X Freq
+    //   0    0     0   fosc/2
+    //   0    0     1   fosc/4
+    //   0    1     0   fosc/8
+    //   0    1     1   fosc/16
+    //   1    0     0   fosc/32
+    //   1    0     1   fosc/64
+    //   1    1     0   fosc/64
+    //   1    1     1   fosc/128
+
+    // We find the fastest clock that is less than or equal to the
+    // given clock rate. The clock divider that results in clock_setting
+    // is 2 ^^ (clock_div + 1). If nothing is slow enough, we'll use the
+    // slowest (128 == 2 ^^ 7, so clock_div = 6).
+    uint8_t clockDiv;
+
+    // When the clock is known at compiletime, use this if-then-else
+    // cascade, which the compiler knows how to completely optimize
+    // away. When clock is not known, use a loop instead, which generates
+    // shorter code.
+    if (__builtin_constant_p(spiClock)) {
+      if (spiClock >= F_CPU / 2)       clockDiv = 0;
+      else if (spiClock >= F_CPU / 4)  clockDiv = 1;
+      else if (spiClock >= F_CPU / 8)  clockDiv = 2;
+      else if (spiClock >= F_CPU / 16) clockDiv = 3;
+      else if (spiClock >= F_CPU / 32) clockDiv = 4;
+      else if (spiClock >= F_CPU / 64) clockDiv = 5;
+      else                             clockDiv = 6;
+    }
+    else {
+      uint32_t clockSetting = F_CPU / 2;
+      clockDiv = 0;
+      while (clockDiv < 6 && spiClock < clockSetting) {
+        clockSetting /= 2;
+        clockDiv++;
+      }
+    }
+
+    // Compensate for the duplicate fosc/64
+    if (clockDiv == 6) clockDiv = 7;
+
+    // Invert the SPI2X bit
+    clockDiv ^= 0x1;
+
+    SPCR = _BV(SPE) | _BV(MSTR) | ((bitOrder == LSBFIRST) ? _BV(DORD) : 0) |
+      (dataMode << CPHA) | ((clockDiv >> 1) << SPR0);
+    SPSR = clockDiv | 0x01;
+  }
+
+
+#else // SOFTWARE_SPI || FORCE_SOFT_SPI
+
+  // ------------------------
+  // Software SPI
+  // ------------------------
+
+  // nop to tune soft SPI timing
+  #define nop asm volatile ("\tnop\n")
+
+  void spiInit(uint8_t) { /* do nothing */ }
+
+  // Begin SPI transaction, set clock, bit order, data mode
+  void spiBeginTransaction(uint32_t spiClock, uint8_t bitOrder, uint8_t dataMode) { /* do nothing */ }
+
+  // Soft SPI receive byte
+  uint8_t spiRec() {
+    uint8_t data = 0;
+    // no interrupts during byte receive - about 8µs
+    cli();
+    // output pin high - like sending 0xFF
+    WRITE(SD_MOSI_PIN, HIGH);
+
+    LOOP_L_N(i, 8) {
+      WRITE(SD_SCK_PIN, HIGH);
+
+      nop; // adjust so SCK is nice
+      nop;
+
+      data <<= 1;
+
+      if (READ(SD_MISO_PIN)) data |= 1;
+
+      WRITE(SD_SCK_PIN, LOW);
+    }
+
+    sei();
+    return data;
+  }
+
+  // Soft SPI read data
+  void spiRead(uint8_t* buf, uint16_t nbyte) {
+    for (uint16_t i = 0; i < nbyte; i++)
+      buf[i] = spiRec();
+  }
+
+  // Soft SPI send byte
+  void spiSend(uint8_t data) {
+    // no interrupts during byte send - about 8µs
+    cli();
+    LOOP_L_N(i, 8) {
+      WRITE(SD_SCK_PIN, LOW);
+      WRITE(SD_MOSI_PIN, data & 0x80);
+      data <<= 1;
+      WRITE(SD_SCK_PIN, HIGH);
+    }
+
+    nop; // hold SCK high for a few ns
+    nop;
+    nop;
+    nop;
+
+    WRITE(SD_SCK_PIN, LOW);
+
+    sei();
+  }
+
+  // Soft SPI send block
+  void spiSendBlock(uint8_t token, const uint8_t* buf) {
+    spiSend(token);
+    for (uint16_t i = 0; i < 512; i++)
+      spiSend(buf[i]);
+  }
+
+#endif // SOFTWARE_SPI || FORCE_SOFT_SPI
+
+#endif // __AVR__