Glossary of the chip-, board-, and Cortex-M85-specific acronyms used in this codebase. Each entry gives a one-line expansion and the HAL driver under libs/ra8_hal/src/ that implements the peripheral (when applicable). Entries are grouped by category for browsing.

Acronym scope: only acronyms that actually appear in libs/ra8_hal/inc/, libs/ra8_hal/src/, or examples/ source. Where an acronym means different things in different vendors' docs, the expansion below is the one Renesas uses in HUM R01UH1065EJ.

1. Clocks, power, reset

Acronym	Expansion	HAL driver
CGC	Clock Generation Circuit	ra8_cgc.c
CAC	Clock-frequency Accuracy-measurement Circuit	ra8_cac.c
LPM	Low Power Mode controller	ra8_lpm.c
LVD	Low-Voltage Detection	ra8_lvd.c
MSTP	Module-Stop control (clock-gating)	ra8_mstp.c
OFS	Option-Function Select (boot configuration words)	ra8_ofs.c
PWR	Power-management glue	ra8_pwr.c
RESET	Reset controller (RSTSR1/2 + cold/warm flags)	ra8_reset.c
SYSC	SYSTEM Controller (R_SYSTEM register block)	(used by ra8_pwr.c, ra8_reset.c, ra8_vreg.c, ra8_lpm.c)
VBATT	Battery-backup domain (VBATT pin / VBTBKR registers)	ra8_bkup.c
VREG	Internal voltage regulator	ra8_vreg.c
BKUP	Battery-backup function (alias for VBATT block)	ra8_bkup.c

2. IO and pin-mux

Acronym	Expansion	HAL driver
GPIO	General-Purpose Input / Output	gpio.c
PORT	Parallel I/O port (PORT0..PORT14 register banks)	gpio.c
PFS	Pin Function Select (per-pin alternate-function register)	gpio.c
PSEL	Pin Select (PFS bitfield choosing the alternate function)	gpio.c
PMR	Port Mode Register (digital vs peripheral)	gpio.c
PDR	Port Direction Register	gpio.c
PODR	Port Output Data Register	gpio.c
PIDR	Port Input Data Register	gpio.c
PWPR	Pin Write-Protect Register (PFS unlock)	gpio.c
PWPRS	Secure Pin Write-Protect Register	gpio.c
PMISC	Pin Miscellaneous (contains PWPR/PWPRS)	gpio.c
MPC	Multi-function Pin Controller	ra8_mpc.c
ELC	Event Link Controller (peripheral-to-peripheral events)	ra8_elc.c
ICU	Interrupt Controller Unit	ra8_icu.c
ISR	Interrupt Service Routine (HAL ISR-table glue)	ra8_isr.c
IRQ	Interrupt Request line (NVIC vector entry)	ra8_icu.c
WUPEN	Wake-Up Enable register	ra8_lpm.c

3. Communication

Acronym	Expansion	HAL driver
SCI	Serial Communications Interface (UART/I2C/SPI super-mode)	ra8_sci.c
UART	Universal Asynchronous Receiver/Transmitter	ra8_sci.c
SPI	Serial Peripheral Interface (controller/peripheral)	ra8_spi_b.c
IIC_B	I2C bus controller, version B (RIIC)	ra8_i2c.c, ra8_i2c_peripheral.c
I3C	Improved Inter-Integrated Circuit (MIPI I3C)	ra8_i3c.c
SMBUS	System Management Bus (I2C-compatible)	ra8_smbus.c
CANFD	Controller Area Network with Flexible Data-rate	ra8_canfd.c
CNECC	CAN Message-RAM ECC controller	ra8_cnecc.c
USB FS	USB Full-Speed (12 Mbps)	ra8_usb.c, ra8_usb_*.c
USB HS	USB High-Speed (480 Mbps)	ra8_usb.c, ra8_usb_*.c
CDC	USB Communications Device Class (virtual COM)	ra8_usb_cdc.c, ra8_usb_hcdc.c, ra8_usb_hcdc_ecm.c
HID	USB Human Interface Device	ra8_usb_phid.c, ra8_usb_hhid.c
MSC	USB Mass Storage Class	ra8_usb_pmsc.c, ra8_usb_hmsc.c
HHUB	USB Host Hub class driver	ra8_usb_hhub.c
PVND	USB Peripheral Vendor-class	ra8_usb_pvnd.c
PAUD/HAUD	USB Peripheral / Host Audio class	ra8_usb_paud.c, ra8_usb_haud.c
PPRN	USB Peripheral Printer class	ra8_usb_pprn.c
ETHA	Ethernet adapter (gigabit MAC top-level)	ra8_etha.c, ra8_eth.c
RMAC	Reduced Media Access Controller (per-port MAC)	ra8_rmac.c, ra8_rmac_phy.c
GWCA	GateWay CPU Agent (Ethernet DMA gateway)	ra8_eth_gwca.c
MFWD	MAC ForWarDing engine	ra8_eth_mfwd.c
ESWM	Ethernet SWitch Management	ra8_layer3_switch.c
GPTP	Generic Precision Time Protocol timer (HUM Ch 35; a timer, not a 1588 message engine)	ra8_eth_gptp.c
TSN	Time-Sensitive Networking	ra8_tsn.c
PHY	Physical-layer transceiver (Ethernet PHY)	ra8_ether_phy.c, ra8_rmac_phy.c
BLE	Bluetooth Low Energy (HCI transport seam; controller on the ESP32-C6 companion)	ra8_ble.c, port/nimble
IPC	Inter-Processor Communication (M85 <-> M33 mailbox)	ra8_ipc.c

4. Crypto and secure-storage

Acronym	Expansion	HAL driver
RSIP	Renesas Secure IP (HW crypto + key vault, RSIP-E50D)	ra8_rsip.c, ra8_rsip_protected.c, ra8_rsip_key_injection.c
DOTF	Decryption-On-The-Fly (XIP-decrypt for xSPI)	ra8_dotf.c
CRC	Cyclic-Redundancy-Check engine	ra8_crc.c
DOC	Data Operation Circuit (compare/add for tamper checks)	ra8_doc.c
MMPU	Bus-initiator Memory Protection Unit	(HAL init only)
CPSCU	Security Control Unit (per-peripheral S/NS attribution)	ra8_lvd.c, ra8_sram.c
BBFSAR	Battery-Backup Full Security Attribute Register	ra8_bkup.c

5. Display, video, graphics

Acronym	Expansion	HAL driver
GLCDC	Graphics LCD Controller (parallel-RGB output)	ra8_glcdc.c
DRW	2D DRaWing engine (DAVE-2D core)	ra8_drw.c
MIPI DSI	MIPI Display Serial Interface	ra8_mipi_dsi.c
MIPI CSI	MIPI Camera Serial Interface	ra8_mipi_csi.c
MIPI PHY	Shared MIPI D-PHY	ra8_mipi_phy.c
CEU	Capture Engine Unit (parallel-camera input)	ra8_ceu.c
VIN	Video INput module	ra8_vin.c
JPEG_SW	Software JPEG codec (no JPEG HW IP on RA8D2)	libs/ra8_jpeg/src/ra8_jpeg_sw.c
EPAPER	E-Paper / EPD framebuffer driver	ra8_epaper.c
TCON	Timing CONtroller (GLCDC TCON0..3 outputs)	ra8_glcdc.c

6. Audio

Acronym	Expansion	HAL driver
SSIE	Serial Sound Interface Enhanced (I2S/TDM)	ra8_ssie.c
PDM	Pulse-Density Modulation microphone interface	ra8_pdm.c
DAI	Digital Audio Interface (CODEC-side I2S signals)	(used in board pin-mux)

7. Analog

Acronym	Expansion	HAL driver
ADC_B	Analog-to-Digital Converter, version B	adc.c
DAC_B	Digital-to-Analog Converter, version B	ra8_dac_b.c
ACMPHS	High-Speed Analog Comparator	ra8_acmphs.c

8. Timers, motor / power

Acronym	Expansion	HAL driver
GPT	General PWM Timer (32-bit, motor / general-purpose)	ra8_gpt.c, timer.c
GTIOC	GPT IO Channel pin (GTIOCnA/B output)	ra8_gpt.c
AGT	Asynchronous General-purpose Timer (16-bit)	ra8_agt.c
ULPT	Ultra-Low-Power Timer	ra8_ulpt.c
POEG	Port Output Enable for GPT (motor-fault shut-off)	ra8_poeg.c
PDG	Phase Delay Generator (multi-channel motor sync)	ra8_pdg.c
WDT	Watchdog Timer	ra8_wdt.c
IWDT	Independent Watchdog Timer	ra8_iwdt.c
RTC	Real-Time Clock	ra8_rtc.c

9. Memory / storage

Acronym	Expansion	HAL driver
MRAM	Magnetoresistive RAM (1 MiB on-chip, code memory)	ra8_flash.c
MRMS	MRAM Module Sequencer (MRAM controller)	ra8_flash.c
SRAM	Static RAM (1664 KiB on-chip, ECC-protected)	ra8_sram.c
ECC	Error-Correcting Code (SRAM/MRAM single-bit correction)	ra8_sram.c, ra8_cnecc.c
DTCM	Data Tightly-Coupled Memory	(linker only)
ITCM	Instruction Tightly-Coupled Memory	(linker only)
TCM	Tightly-Coupled Memory (umbrella for ITCM + DTCM)	(linker only)
SDRAM	Synchronous Dynamic RAM (external, 64 MiB on EK)	ra8_sdramc.c
SDRAMC	SDRAM Controller	ra8_sdramc.c
OSPI	Octo-SPI (Renesas register block name)	ra8_xspi.c
XSPI	eXpanded SPI (xSPI = HUM term for the OSPI controller)	ra8_xspi.c
XIP	eXecute-In-Place (memory-mapped read of external flash)	ra8_xspi.c
FLASH	Generic flash controller surface	ra8_flash.c
SDHI	SD Host Interface	ra8_sdhi.c, ra8_sdcard.c
DMA	Direct Memory Access (top-level umbrella)	ra8_dma.c
DMAC	Direct Memory Access Controller	ra8_dmac.c
DTC	Data Transfer Controller (lighter-weight than DMAC)	ra8_dtc.c
DOTF	Decryption-On-The-Fly (covered under crypto above)	ra8_dotf.c

10. Debug, test, NVIC / core

Acronym	Expansion	HAL driver
BSCAN	Boundary Scan controller	ra8_bscan.c
HW ERR	Hardware-Error reporter	ra8_hw_err.h
MMIO	Memory-Mapped I/O (generic term, not a Renesas IP)	–
NVIC	Nested Vectored Interrupt Controller (Cortex-M core)	(used by ra8_icu.c)
SCB	System Control Block (Cortex-M core)	(used by HAL fault handlers)
MPU	Memory Protection Unit (core MPU at 0xE000ED90)	(HAL init)
MMPU	Bus-initiator MPU (chip-level, distinct from core MPU)	(HAL init)
FPU	Floating-Point Unit (Cortex-M85 single+double precision)	(toolchain flags)
MVE	M-profile Vector Extension (a.k.a. Helium)	(toolchain flags)
Helium	ARM marketing name for MVE	(toolchain flags)
SAU	Security Attribution Unit (TrustZone partitioning)	per-app trustzone_init.c
NSC	Non-Secure Callable (TrustZone veneers)	libs/ra8_nsc/

11. Touch and sensors

Acronym	Expansion	HAL driver
TOUCH	Capacitive-touch driver (GT911 panel, parallel TFT)	ra8_touch.c

12. Vendor / family acronyms

Acronym	Expansion
RA	Renesas Advanced (32-bit Arm-based MCU family)
RA8D2	RA8 family, "D" = Display-class, group 2
FSP	Flexible Software Package (Renesas reference SDK; not in this tree)
HUM	Hardware User's Manual (R01UH1065EJ)
EK	Evaluation Kit (EK-RA8D2 v1 board)
OB	On-Board (J-Link OB on the EK)
Pmod	Digilent Peripheral Module connector
TFT	Thin-Film-Transistor LCD panel