diff options
Diffstat (limited to 'c/src/lib/libbsp/arm/atsam/README')
| -rw-r--r-- | c/src/lib/libbsp/arm/atsam/README | 25 |
1 files changed, 22 insertions, 3 deletions
diff --git a/c/src/lib/libbsp/arm/atsam/README b/c/src/lib/libbsp/arm/atsam/README index 5f53d5f5e9..e21e7ee405 100644 --- a/c/src/lib/libbsp/arm/atsam/README +++ b/c/src/lib/libbsp/arm/atsam/README @@ -17,9 +17,28 @@ controller and speed combinations. Use BOARD_MAINOSC=XYZ to set the main oscillator frequency in Hz (default 12MHz). -Use BOARD_MCK=XYZ to set the Master Clock (MCK) frequency in Hz (default -123MHz). The default value enables operation of an external SDRAM, e.g. 150MHz -would be too fast. +Use ATSAM_MCK=XYZ to set the MCK frequency that should be used. The default case +(123000000) enables operation of an external SDRAM on the SAMv71 Explained +evaluation kit. Some other configurations (e.g. 150MHz) would be too fast on +that board. + +Your application can also overwrite the clock settings. To overwrite the clock +settings, define the following structures in your application: + +-------- +const struct atsam_clock_config atsam_clock_config = { + .pllar_init = my_custom_pllar_value, + .mckr_init = my_custom_mckr_value, + .mck_freq = my_resulting_mck_frequency +}; + +const struct BOARD_Sdram_Config BOARD_Sdram_Config = { + .sdramc_tr = my_custom_sdramc_tr_value, + .sdramc_cr = my_custom_sdramc_cr_value, + .sdramc_mdr = my_custom_sdramc_mdr_value, + .sdramc_cfr1 = my_custom_sdramc_cfr1_value +}; +-------- Use ATSAM_CONSOLE_BAUD=XYZ to set the initial baud for console devices (default 115200). |