Microchip SPI SRAM (23LC1024, 23LC512) access library.
23LCxx_SPI.cpp
- Committer:
- discypus
- Date:
- 2015-11-26
- Revision:
- 0:625ac56d810e
- Child:
- 1:56e01e806364
File content as of revision 0:625ac56d810e:
#include <mbed.h> #include "23LCxx_SPI.h" /** SPI COMMAND (Microchip 23LC1024, 23K256 SPI SRAM) */ enum Microchip23LC1024Commnd { READ = 0x03u, WRITE = 0x02u, EDIO = 0x3bu, EQIO = 0x38u, RSTIO = 0xffu, RDMR = 0x05u, WRMR = 0x01u, }; Microchip23LCxx::Microchip23LCxx(PinName mosi, PinName miso, PinName sck, PinName cs, uint32_t hz) : _spi(mosi, miso, sck), _cs(cs) { _spi.format(8, 0); // 8bit, mode=0 _spi.frequency(hz); // max 20MHz (20*1000*1000) in 23LC1024. _cs = 1; } uint8_t Microchip23LCxx::read_mode_register() { _cs = 0; _spi.write(RDMR); const uint8_t value = _spi.write(0x00); _cs = 1; return value; } void Microchip23LCxx::write_mode_register(const uint8_t value) { _cs = 0; _spi.write(WRMR); _spi.write(value); _cs = 1; } uint8_t Microchip23LCxx::change_mode(const uint8_t next_mode) { const uint8_t previous_register = read_mode_register(); const uint8_t previous_mode = previous_register & MODE_MASK; if (next_mode != previous_mode) { const uint8_t next_register = (previous_register & ~MODE_MASK) | uint8_t(next_mode); write_mode_register(next_register); } return previous_mode; } void Microchip23LCxx::_set_address(const uint32_t address) { const uint8_t address_high = (address >> (8 * 2)) & 0xFFu; const uint8_t address_mid = (address >> (8 * 1)) & 0xFFu; const uint8_t address_low = (address >> (8 * 0)) & 0xFFu; _spi.write(address_high); _spi.write(address_mid); _spi.write(address_low); } uint8_t Microchip23LCxx::read_byte(const uint32_t address) { _cs = 0; _spi.write(READ); _set_address(address); const uint8_t data = _spi.write(0); _cs = 1; return data; } void Microchip23LCxx::write_byte(const uint32_t address, const uint8_t data) { _cs = 0; _spi.write(WRITE); _set_address(address); _spi.write(data); _cs = 1; } /** * multi-byte read * @pre sequential mode or page mode is required. */ void Microchip23LCxx::read_bytes(const uint32_t address, uint8_t __restrict data[], const uint32_t size) { _cs = 0; _spi.write(READ); _set_address(address); for (uint32_t i = 0; i < size; ++i) { data[i] = _spi.write(0x00u); } _cs = 1; } /** * multi-byte write * @pre sequential mode or page mode is required. */ void Microchip23LCxx::write_bytes(const uint32_t address, const uint8_t __restrict data[], const uint32_t size) { _cs = 0; _spi.write(WRITE); _set_address(address); for (uint32_t i = 0; i < size; ++i) { _spi.write(data[i]); } _cs = 1; }