src/include/sdram_mode.h

   1 /* SPDX-License-Identifier: GPL-2.0-or-later */
   2
   3 /*
   4  * sdram_mode.h: Definitions for SDRAM Mode Register and Extended Mode Register
   5  */
   6
   7 #ifndef __SDRAMMODE_H_DEFINED
   8 #define __SDRAMMODE_H_DEFINED
   9
  10 // SDRAM Mode Register definitions, per JESD79D
  11 // These are transmitted via A0-A13
  12
  13 // Burst length
  14 #define SDRAM_BURST_2     (1<<0)
  15 #define SDRAM_BURST_4     (2<<0)
  16 #define SDRAM_BURST_8     (3<<0)
  17
  18 #define SDRAM_BURST_SEQUENTIAL  (0<<3)
  19 #define SDRAM_BURST_INTERLEAVED (1<<3)
  20
  21 #define SDRAM_CAS_2_0     (2<<4)
  22 #define SDRAM_CAS_3_0     (3<<4)        /* Optional for DDR 200-333 */
  23 #define SDRAM_CAS_1_5     (5<<4)        /* Optional */
  24 #define SDRAM_CAS_2_5     (6<<4)
  25 #define SDRAM_CAS_MASK    (7<<4)
  26
  27 #define SDRAM_MODE_NORMAL               (0 << 7)
  28 #define SDRAM_MODE_TEST         (1 << 7)
  29 #define SDRAM_MODE_DLL_RESET    (2 << 7)
  30
  31 // Extended Mode Register
  32
  33 #define SDRAM_EXTMODE_DLL_ENABLE        (0 << 0)
  34 #define SDRAM_EXTMODE_DLL_DISABLE       (1 << 0)
  35
  36 #define SDRAM_EXTMODE_DRIVE_NORMAL      (0 << 1)
  37 #define SDRAM_EXTMODE_DRIVE_WEAK        (1 << 1)        /* Optional */
  38
  39 #endif  // __SDRAMMODE_H_DEFINED