SPRUIE9D May 2017 – May 2024 DRA74P , DRA75P , DRA76P , DRA77P
The RESIZER module can do handshaking with ICM. For this purpose, RESIZER has two input signals (P_START_A/B) and two output signals (P_DONE_A/B) for each channel.
Signal name | Direction | Description |
---|---|---|
P_START_A | Input | Process start signal from ICM to RSZ_A This signal is used for YUV422 mode and Y channel of YUV420 |
P_DONE_A | Output | Process done signal from RSZ_A to ICM. This signal is used for YUV422 mode and Y channel of YUV420 |
P_DONE_AC | Output | Process done signal from RSZ_A Chroma Channel to ICM. This signal is used only for C channel of YUV420 |
P_START_B | Input | Process start signal from ICM to RSZ_B. This signal is used for YUV422 mode and Y channel of YUV420. In ISS configuration, this signal is tied ‘1’ at ISS level. |
P_DONE_B | Output | Process done signal from RSZ_B to ICM This signal is used for YUV422 mode and Y channel of YUV420. In ISS6 configuration, this signal is left open. |
P_DONE_BC | Output | Process done signal from RSZ_B Chroma Channel to ICM. This signal is used only for C channel of YUV420 |
P_DONE_X (X=A/AC/B/BC) is high for 2 to 4 ISS_MAIN_FCLK cycles.
In ISS implementation, handshake between RSZB and ICM is not implemented. Therefore, P_START_B is tied "high" at ISS6 level. RSZ must be designed so that, it can operate if any of P_START_A/AC/B/BC is always "1''.
When handshaking is enabled (RSZ_IRQ_RZA[16] ICMA_EN=1 or RSZ_IRQ_RZB[16] ICMB_EN=1), RESIZE operate its RSZ_A output port in the following manner.
For RSZ_B, the process is exactly the same except the signals are P_START_B and P_DONE_B, and the parameters is RSZ_IRQ_RZB RZB. (RSZ_IRQ_RZA RZA and RSZ_IRQ_RZB RZB are shared with IRQ cycles.)
If P_START_A/B signal is not asserted for an extended period, and if the input buffer becomes close to buffer over flow, RSZ_INPUT_STALL signal must be asserted to suspend the input stream
RSZ starts ICM handshake and starts checking P_START_x signals only after it is enabled.
Example-1: RSZ in single shot mode: RSZ is enabled at the frame start after the first crop, and this timing is notified to SW through rsz_int_reg event. If P_START is sent to RSZ before this moment (rsz_int_reg), it is ignored. ICM Handshake must start after rsz_int_reg interrupt.
Example-2: RSZ in single shot mode: For each frame, RSZ is enabled at the frame start after the first crop (= rsz_int_reg issue timing). Any P_START received between the EOF of the last frame and the current frame start (rsz_int_reg) is ignored. ICM handshake for each frame must be started after rsz_int_reg interrupt.