pounder_test/src/design_parameters.rs

use super::hal::time::MegaHertz;

/// The ADC setup time is the number of seconds after the CSn line goes low before the serial clock
/// may begin. This is used for performing the internal ADC conversion.
pub const ADC_SETUP_TIME: f32 = 220e-9;

/// The maximum DAC/ADC serial clock line frequency. This is a hardware limit.
pub const ADC_DAC_SCK_MAX: MegaHertz = MegaHertz(50);

/// The optimal counting frequency of the hardware timers used for timestamping and sampling.
pub const TIMER_FREQUENCY: MegaHertz = MegaHertz(100);

/// The QSPI frequency for communicating with the pounder DDS.
pub const POUNDER_QSPI_FREQUENCY: MegaHertz = MegaHertz(40);

/// The delay after initiating a QSPI transfer before asserting the IO_Update for the pounder DDS.
// Pounder Profile writes are always 16 bytes, with 2 cycles required per byte, coming out to a
// total of 32 QSPI clock cycles. The QSPI is configured for 40MHz, so this comes out to an offset
// of 800nS. We use 900ns to be safe.
pub const POUNDER_IO_UPDATE_DELAY: f32 = 900_e-9;

/// The duration to assert IO_Update for the pounder DDS.
// IO_Update should be latched for 4 SYNC_CLK cycles after the QSPI profile write. With pounder
// SYNC_CLK running at 100MHz (1/4 of the pounder reference clock of 500MHz), this corresponds to
// 32ns. To accomodate rounding errors, we use 50ns instead.
pub const POUNDER_IO_UPDATE_DURATION: f32 = 50_e-9;

/// The DDS reference clock frequency in MHz.
pub const DDS_REF_CLK: MegaHertz = MegaHertz(100);

/// The multiplier used for the DDS reference clock PLL.
pub const DDS_MULTIPLIER: u8 = 5;

/// The DDS system clock frequency after the internal PLL multiplication.
pub const DDS_SYSTEM_CLK: MegaHertz =
    MegaHertz(DDS_REF_CLK.0 * DDS_MULTIPLIER as u32);

/// The divider from the DDS system clock to the SYNC_CLK output (sync-clk is always 1/4 of sysclk).
pub const DDS_SYNC_CLK_DIV: u8 = 4;