ra8_ceu.h File Reference

Capture Engine Unit (CEU) camera-capture driver. More...

#include <stdint.h>
#include "ra8_ceu_api.h"
#include "ra8_ceu_regs.h"
#include "ra8_ceu_types.h"
#include "ra8_err.h"

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Detailed Description

Capture Engine Unit (CEU) camera-capture driver.

Tag

[Ring 3 / HAL] {World: NS}

Full-coverage HAL driver for the RA8D2 Capture Engine Unit. The CEU is the parallel camera-input path that DMAs frames from an external CMOS sensor (the EK-RA8D2's on-board OV5640) into SRAM/SDRAM. This driver implements every operating mode and register field documented in HUM Ch 60 (p 3626-3682):

• Image-capture mode (CAMCR.JPG = 00) – YCbCr 4:2:2 input, optional hardware conversion to YCbCr 4:2:0, optional bilinear scale-down, optional input-low-pass pre-filter.
• Data-synchronous-fetch mode (CAMCR.JPG = 01) – raw sensor pixels at HD/VD timing, no Y/C separation.
• Data-enable-fetch mode (CAMCR.JPG = 10) – gated capture of byte-stream data (e.g. JPEG payloads); CFWCR firewall is armed automatically here.
• Single-shot vs continuous capture (CAPCR.CTNCP).
• Bundle write mode (CDOCR.CBE) with 4-address ping-pong across CDAYR / CDAYR2 / CDBYR / CDBYR2.
• Interlace capture with both-field or one-field clipping (CAIFR.IFS / CIM, CAMCR.FLDPOL/FLDSEL, CDBYR/CDBCR programming).
• Plane B shadow programming for in-flight reconfiguration across a VD edge plus the forced-swap (CRCMPR.RA) escape hatch.
• Byte swap at 8/16/32-bit granularity (CDOCR.COBS / COWS / COLS).
• TrustZone-style firewall (CFWCR) capping the legal write window during data-enable fetch.
• Frame-drop counter (CAPCR.FDRP) and burst-mode size (CAPCR.MTCM, 32/64/128/256-byte transfers).
• Edge select for the data lines, HD, VD, FLD inputs (CAMCR.DSEL / HDSEL / VDSEL / FLDSEL).
• Every IRQ source documented in CETCR – frame end, field end, illegal register write, HD, VD, four bundle-end events, CRAM overflow, HD/VD mismatch, VD error, firewall fault, HD missing, VD missing – with a registered callback dispatch.
• Lifecycle: init / deinit / reset / enter_stop / exit_stop plus a dedicated software-reset path bounded by a CSTSR.CPTON spin with k_ra8_err_hw_timeout on overrun.
• Status: CSTSR snapshot (CPTON, CPFLD field, CRST plane), CDSSR byte-count read after data-enable capture.

Driver state machine

State Machine:

From	Trigger	To
Closed	ra8_ceu_init	Idle
Idle	ra8_ceu_capture_start	Capturing
Capturing	CPE (single-shot)	Idle
Capturing	ra8_ceu_capture_stop	Idle
Capturing	ra8_ceu_reset	Idle
Idle	ra8_ceu_enter_stop	Stopped
Stopped	ra8_ceu_exit_stop	Idle
Idle	ra8_ceu_deinit	Closed

The driver does not maintain explicit state – the state is derived from CSTSR.CPTON, CAPSR.CE / CPKIL and the CEIER mask. Every public API checks the live register state before issuing a mode change so the table above is observable, not enforced via a private state variable.

Umbrella header

This file is a thin umbrella. The driver declarations live in the concern-split sub-headers below and are pulled in verbatim; every consumer that #include "ra8_ceu.h" continues to see the full API:

• ra8_ceu_types.h – configuration descriptors, enums, register-bundle structs, status snapshot, event-callback typedef.
• ra8_ceu_api.h – lifecycle, status/IRQ, power, capture, live-reconfig setters, and DMA-coupling function prototypes.

Copyright

Copyright (c) 2026 Brighton Sikarskie SPDX-License-Identifier: MIT

Definition in file ra8_ceu.h.