For a better timing and control, the valid control lines are gated with flops, instead of combinatorial logic.
This is the main reason why we do not need the tdd_enable_synced signal anymore. The out coming data is delayed by one clock cycle to keep data and control lines synced.
+ Define two control signal for util_tdd_sync : tdd_sync_en and tdd_terminal_type
+ Delete to old ad_tdd_sync.v instances from the core
+ Update Make files
+ Update ad_tdd_control: add additional CDC logic for tdd_sync (the sync comes from another clock domain)
+ Update the ad_tdd_sync module: it's just a simple pulse generator, the pulse period is defined using a parameter, pulse width is fixed: 128 x clock cycle
+ Update TDD regmap: tdd sync period is no longer software defined
The synchronization interface is a single bidirectional line. Output for Master, input for Slave.
The sync_period value is relative to frame length and the digital interface clock. The actual synchronization
period will be: sync_period * frame_length * fb_clock_cycle
This line controls the mux, which switch between hdl and software (GPIO) control of the ENABLE/TXNRX pins.
Fix the broken path and change the name from "tdd_enable" to "tdd_enabled".
Supported carrier are ZC706 and RFSOM.
The synchronization pulse is automatically generated by the master terminal, when TDD mode is enabled.
By default a terminal is slave, software must write 0x01 into TDD register 0x50.
Add tdd_gated_[tx/rx]_dmapath control bits to the TDD logic. With these control line, the user can choose between gated and free-running (like in FDD mode) data flow control.
In FDD mode the tx_valid_* signals are generated inside the axi_ad9361_tx module, in function of
the selected dac data rate. In TDD mode, these signals are gated by the tdd_enable and tdd_tx_dp_en signals.
In other words, the tx_valid_* signals will be valid just when tdd_enable and tdd_tx_dp_en is active.
+ Delete unnecessary registers
+ Add the module ad_addsub.v to resolve additions and subtractions inside TDD control
+ Redefine the burst logic
+ Redesign the control signal generations
+ Note: This patch fix the TDD related timing violations
Istvan Csomortani