Source code example:
Code: Select all
/**
*
* IPS6404 8 MB PSRAM (SPI SRAM) Write/Read example
*
* (c) 2019 by Vassilis Serasidis <avrsite@yahoo.gr>
* Home: https://www.serasidis.gr
* Forum: https://mcu.selfip.com , https://www.stm32duino.com
*
* Target: STM32F103C8 (Bluepill) at 72 MHz
* Core: STM official (https://github.com/stm32duino/Arduino_Core_STM32)
* IDE: Arduino 1.8.9
*/
#include <SPI.h>
#define PSRAM_CS PA4
#define BUFFER_LENGTH 8192
#define WRITE_TO_PSRAM 0x02
#define READ_FROM_PSRAM 0x03
uint32_t tmr;
uint8_t tmp_buffer[BUFFER_LENGTH];
/***************************************************
*
**************************************************/
void setup() {
pinMode(PSRAM_CS, OUTPUT);
digitalWrite(PSRAM_CS, HIGH);
Serial.begin(9600);
SPI.begin();
SPI.beginTransaction(SPISettings(72000000, MSBFIRST, SPI_MODE0));
psram_reset(); //Reset the PSRAM chip
}
/***************************************************
*
**************************************************/
void loop() {
psram_read_id();
/* Fill the temporary buffer with data */
for(uint32_t i=0;i<BUFFER_LENGTH;i++){
tmp_buffer[i] = i;
}
/* Write 8192 byte buffer to PSRAM */
Serial.print("Writing ");
Serial.print(BUFFER_LENGTH);
Serial.print(" bytes to PSRAM (");
tmr = millis();
psram_data(WRITE_TO_PSRAM, 0, tmp_buffer, BUFFER_LENGTH); //Write <tmp_buffer> to PSRAM
tmr = (millis() - tmr);
Serial.print(tmr);
Serial.println(" ms)");
/* Clear temporary buffer */
for(uint32_t i=0;i<BUFFER_LENGTH;i++){
tmp_buffer[i] = 0xff;
}
/* Read 8192 bytes from PSRAM */
Serial.print("Reading ");
Serial.print(BUFFER_LENGTH);
Serial.print(" bytes from PSRAM (");
tmr = millis();
psram_data(READ_FROM_PSRAM, 0, tmp_buffer, BUFFER_LENGTH); //Read data from PSRAM to <tmp_buffer>
tmr = (millis() - tmr);
Serial.print(tmr);
Serial.println(" ms)");
for(uint32_t i=0;i<BUFFER_LENGTH;i++){
if((i%16) == 0){ //Change line every 16 bytes
Serial.println();
}
if(tmp_buffer[i] < 0x10){ //Print an ASCII zero in case the value is lower than 0x10
Serial.write('0');
}
Serial.print(tmp_buffer[i], HEX);
Serial.write(' ');
}
Serial.println("\n\nComplete !\n\n");
delay(1000);
}
/***************************************************
*
**************************************************/
uint8_t psram_read_id(){
uint8_t data;
digitalWrite(PSRAM_CS, LOW);
SPI.transfer(0x9F);
Serial.print("ID: ");
for(int i=0;i<6;i++){
data = SPI.transfer(0xff);
if(data < 0x10){
Serial.write('0');
}
Serial.print(data, HEX);
Serial.write(' ');
}
digitalWrite(PSRAM_CS, HIGH);
Serial.println();
}
/***************************************************
*
**************************************************/
void psram_reset(){
digitalWrite(PSRAM_CS, LOW);
SPI.transfer(0x66);
digitalWrite(PSRAM_CS, HIGH);
digitalWrite(PSRAM_CS, LOW);
SPI.transfer(0x99);
digitalWrite(PSRAM_CS, HIGH);
}
/***************************************************
* Read or Write <len> bytes from/to PSRAM
**************************************************/
void psram_data(uint8_t cmd, uint32_t address, uint8_t *buf, uint32_t len){
uint8_t data;
digitalWrite(PSRAM_CS, LOW);
SPI.transfer(cmd);
SPI.transfer((uint8_t)((address >> 16) & 0xFF)); //Address [23:16]
SPI.transfer((uint8_t)((address >> 8) & 0xFF)); //Address [15:8]
SPI.transfer((uint8_t)(address & 0xFF)); //Address [7:0]
SPI.transfer(buf, len);
digitalWrite(PSRAM_CS, HIGH);
}
Code: Select all
ID: FF FF FE 0D 5D 46
Writing 8192 bytes to PSRAM (11 ms)
Reading 8192 bytes from PSRAM (11 ms)
00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F
10 11 12 13 14 15 16 17 18 19 1A 1B 1C 1D 1E 1F
20 21 22 23 24 25 26 27 28 29 2A 2B 2C 2D 2E 2F
30 31 32 33 34 35 36 37 38 39 3A 3B 3C 3D 3E 3F
40 41 42 43 44 45 46 47 48 49 4A 4B 4C 4D 4E 4F
...
...
D0 D1 D2 D3 D4 D5 D6 D7 D8 D9 DA DB DC DD DE DF
E0 E1 E2 E3 E4 E5 E6 E7 E8 E9 EA EB EC ED EE EF
F0 F1 F2 F3 F4 F5 F6 F7 F8 F9 FA FB FC FD FE FF
Complete !
