AP_CTRL - 1.4.1 English

Vitis AI RNN User Guide (UG1563)

Document ID
UG1563
Release Date
2021-12-03
Version
1.4.1 English

The ap_ctrl register controls and provides the kernel status. The host uses it to control the start and acknowledge the end of the kernel process. The host writes a 1 in ap_start and waits for both ap_start to be deasserted (guaranteeing the input data is fully processed) and ap_done to be asserted (guaranteeing the output data is fully produced). Definitions of the control register bits are listed in the following table. The address is 0x0. The kernel can and should only be restarted after it finishes the current workload and is in the idle state.

Bit Register Address Type Description
0 ap_start 0x0 W Asserted by host when kernel can start processing data. Cleared by kernel on handshake with ap_ready.
1 ap_done R Asserted by kernel when it has finished producing output data. Cleared on read by host.
2 ap_idle R Asserted by kernel when it is idle (deprecated).
3 ap_ready R Asserted by kernel when it has finished processing input data. Self-cleared immediately.
6:4 reserved   Reserved
7 auto_restart R/W If asserted, ap_start is held asserted by the kernel. Read/write access by the host. (Not used)
31:8 reserved   Reserved