pub struct SimpleCodec<const HEADER_SIZE: usize, const ADDR_MSB: u8, const ADDR_LSB: u8, const RW_BIT: u8, const RW_1_IS_READ: bool, const READ_DELAY: usize> {}Expand description
This codec represents the most commonly found codecs for SPI devices. It consists of an N-bit big-endian register address, a 1-bit R/W indicator and uses zero initializion for reserved bits. The header is always a multiple of 8-bit in width.
This codec has no information over register sizes or the existence of read/write address-auto-increment which some devices support. It will always send one header and then receive/send the associated register data, so it’s compatible with auto-increment usage, but cannot be used to read or write registers that require interspersing the address between bytes.
Devices often use a mixed mode, where some registers allow auto-increment while others don’t, or where the address is directly associated with a specific, but varying, register size. Therefore, it is up to the user to make sure that accessing a register via this codec is supported by the hardware.
The following generic parameters are available:
| Parameter | Type | Description |
|---|---|---|
HEADER_SIZE | usize | The size of the command header in bytes |
ADDR_MSB | u8 | The bit index of the MSB of the register-address (inclusive) |
ADDR_LSB | u8 | The bit index of the LSB of the register-address (inclusive) |
RW_BIT | u8 | The bit index of the RW bit when interpreting the struct in big-endian |
RW_1_IS_READ | bool | whether the setting the RW bit signals read-mode (true) or write-mode (false) |
READ_DELAY | usize | Number of bytes that we have to wait (send additional zeros) after sending the header until data arrives |