====== Memory components ======

The GECKO4-Education platform contains a SDRAM and serial flash memory as indicated in the below figure.

{{ :gecko4education:sdram_flash.png?200 |}}

===== SDRAM information =====
The GECKO4-Education contains a 32MByte mobile synchronous DRAM (M-SDRAM). The datasheets can be found {{:gecko4education:is42vm16160k.pdf|here}}.

This SDRAM can be used with the external SDRAM memory controller of QSYS. The below tables indicate the FPGA-pins to which the SDRAM is connected. And {{:gecko4education:sdram.tcl|here}} you find an example tcl script that can be used for pin-assignment in Quartus.

**Address bus:**
|Address bit:|12    |11    |10    |9     |8     |7     |6     |5     |4     |3     |2     |1     |0     |
|FPGA-pin:   |PIN_V2|PIN_U8|PIN_U2|PIN_V4|PIN_V1|PIN_V5|PIN_V6|PIN_V7|PIN_W6|PIN_P5|PIN_P4|PIN_N6|PIN_N5|

**Data bus:**
|Data bit:|15     |14     |13     |12    |11    |10    |9     |8     |7     |6     |5     |4     |3     |2     |1     |0     |
|FPGA-pin:|PIN_AA4|PIN_AB3|PIN_AA1|PIN_Y3|PIN_Y2|PIN_Y1|PIN_W2|PIN_W1|PIN_P3|PIN_P2|PIN_P1|PIN_N2|PIN_N1|PIN_M3|PIN_M2|PIN_M1|

**Control signals:**
^Function:                        ^short:^FPGA-pin:^
|Bank Select high                 |BA[1] |PIN_M7   |
|Bank Select low                  |BA[0] |PIN_M6   |
|Byte Select high                 |DQM[1]|PIN_V3   |
|Byte Select low                  |DQM[0]|PIN_R1   |
|Clock enable                     |CKE   |PIN_U7   |
|Clock                            |CLK   |PIN_AA3  |
|Colum address select (active low)|nCAS  |PIN_M5   |
|Row address select (active low)  |nRAS  |PIN_M4   |
|Chip select (active low)         |nCS   |PIN_U1   |
|Write enable (active low)        |nWE   |PIN_R2   |
===== Flash information =====
The GECKO4-Education board contains besides the FPGA-configuration FLASH also a 8MByte serial FLASH memory. The datasheets of this component is available {{:gecko4education:s25fl1-k_00.pdf|here}}.

The below table shows the FPGA-pin connections. And {{:gecko4education:flash.tcl|here}} you find an example tcl script that can be used for pin-assignment in Quartus.

^Function:                        ^short:   ^FPGA-pin:^
|Chip select (active low)         |NCS      |PIN_U14  |
|Hold (active low) or IO3         |NHOLD_IO3|PIN_U13  |
|Serial clock                     |SCK      |PIN_V13  |
|Serial in or IO0                 |SI_IO0   |PIN_W13  |
|Serial out or IO1                |SO_IO0   |PIN_V14  |
|Write protect (active low) or IO2|NWP_IO2  |PIN_W14  |