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software/liblitedram: selectable write leveling MR (for LPDDR4 support)

This commit is contained in:
Jędrzej Boczar 2020-12-23 11:22:43 +01:00
parent 7abfbd9825
commit 38b819c42a
1 changed files with 9 additions and 8 deletions
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17
litex/soc/software/liblitedram/sdram.c
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@ -260,13 +260,14 @@ int _sdram_write_leveling_cdly_range_end = -1;
static void sdram_write_leveling_on(void)
{
sdram_dfii_pi0_address_write(DDRX_MR1 | (1 << 7));
sdram_dfii_pi0_baddress_write(1);
// Flip write leveling bit in the Mode Register, as it is disabled by default
sdram_dfii_pi0_address_write(DDRX_MR_WRLVL_RESET ^ (1 << DDRX_MR_WRLVL_BIT));
sdram_dfii_pi0_baddress_write(DDRX_MR_WRLVL_ADDRESS);
command_p0(DFII_COMMAND_RAS|DFII_COMMAND_CAS|DFII_COMMAND_WE|DFII_COMMAND_CS);
#ifdef SDRAM_PHY_DDR4_RDIMM
sdram_dfii_pi0_address_write((DDRX_MR1 | (1 << 7)) ^ 0x2BF8) ;
sdram_dfii_pi0_baddress_write(1 ^ 0xF);
sdram_dfii_pi0_address_write((DDRX_MR_WRLVL_RESET ^ (1 << DDRX_MR_WRLVL_BIT)) ^ 0x2BF8) ;
sdram_dfii_pi0_baddress_write(DDRX_MR_WRLVL_ADDRESS ^ 0xF);
command_p0(DFII_COMMAND_RAS|DFII_COMMAND_CAS|DFII_COMMAND_WE|DFII_COMMAND_CS);
#endif
@ -275,13 +276,13 @@ static void sdram_write_leveling_on(void)
static void sdram_write_leveling_off(void)
{
sdram_dfii_pi0_address_write(DDRX_MR1);
sdram_dfii_pi0_baddress_write(1);
sdram_dfii_pi0_address_write(DDRX_MR_WRLVL_RESET);
sdram_dfii_pi0_baddress_write(DDRX_MR_WRLVL_ADDRESS);
command_p0(DFII_COMMAND_RAS|DFII_COMMAND_CAS|DFII_COMMAND_WE|DFII_COMMAND_CS);
#ifdef SDRAM_PHY_DDR4_RDIMM
sdram_dfii_pi0_address_write(DDRX_MR1 ^ 0x2BF8);
sdram_dfii_pi0_baddress_write(1 ^ 0xF);
sdram_dfii_pi0_address_write(DDRX_MR_WRLVL_RESET ^ 0x2BF8);
sdram_dfii_pi0_baddress_write(DDRX_MR_WRLVL_ADDRESS ^ 0xF);
command_p0(DFII_COMMAND_RAS|DFII_COMMAND_CAS|DFII_COMMAND_WE|DFII_COMMAND_CS);
#endif