Function details-9

8.2.9 Register access

List

Title Function specifications

Function Get data transfer register pointer

Function Name [-] CDC_GetDataPtr

No 9.1

Form

Uint32 * CDC_GetDataPtr (void)

input

none

output

none

Function value

Register pointer (address value)

function

Gets a pointer to the data transfer register (DATATRNS).

(1) Access method

There are three types of data transfer methods for data transfer registers and MPEG registers.

• DMA transfer by SCU
• DMA transfer by CPU
• Software transfer by CPU

Registers must be accessed longword (32-bit) for CPU-based DMA transfers and software transfers. In other words, the data to be transferred is in longword (even word) units.
Data that has been accessed for a long word is stored in the order of upper word and lower word. When transferring odd-word data, the subword of the last longword access is undefined.

(2) Volatile declaration

When assigning a pointer to a variable, a volatile declaration is required to prevent incorrect optimization.

example

volatile Uint32 * ptr;
ptr = CDC_GetDataPtr ();

List

Title Function specifications

Function Acquisition of interrupt cause register value

Function Name [-] CDC_GetHirqReq

No 9.2

Form

Sint32 CDC_GetHirqReq (void)

input

none

output

none

Function value

Register value …… Refer to the data specification (Constant) for the bit name.

function

Acquires the value of the interrupt cause register (HIRQREQ).

List

Title Function specifications

Function Clear interrupt factor register

Function Name [-] CDC_ClrHirqReq

No 9.3

Form

void CDC_ClrHirqReq (Sint32 bitpat)

input

bitpat: Clear bit pattern (set the bit you want to clear to 0 and the others to 1)

output

none

Function value

none

function

The interrupt cause register is cleared according to the specified bit pattern.

remarks

The CMOK flag in the interrupt cause register is used by the CD communication interface, so clearing by the application program is prohibited. Also, the DCHG flag is cleared by the BOOT ROM when the disk is checked, so do not clear it when initializing the application program. (As an exception, it can be cleared only when processing DCHG interrupts)

List

Title Function specifications

Function Get interrupt mask register value

Function Name [-] CDC_GetHirqMsk

No 9.4

Form

Sint32 CDC_GetHirqMsk (void)

input

none

output

none

Function value

Register value …… Refer to the data specification (Constant) for the bit name.

function

Gets the value of the interrupt mask register (HIRQMSK).

List

Title Function specifications

Function Interrupt mask register setting

Function Name [-] CDC_SetHirqMsk

No 9.5

Form

void CDC_SetHirqMsk (Sint32 bitpat)

input

bitpat: Mask bit pattern (set the bit you want to mask to 0 and the others to 1)

output

none

Function value

none

function

Sets the interrupt mask register according to the specified bit pattern.

List

Title Function specifications

Function Get MPEG register pointer

Function Name [-] CDC_GetMpegPtr

No 9.6

Form

Uint32 * CDC_GetMpegPtr (void)

input

none

output

none

Function value

Register pointer (address value)

function

Acquires a pointer to the MPEG register (MPEGRGB).
The access method of the MPEG register is the same as that of the data transfer register. For notes, etc., refer to Obtaining the data transfer register pointer ( CDC_GetDataPtr).