38K0 datasheet(46/328 Pages) RENESAS

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FUNCTIONAL DESCRIPTION

Rev.2.00

Oct 05, 2006

page 29 of 112

38K0 Group

REJ09B0337-0200

HARDWARE

Endpoint Buffer Area Setting

The buffer area used in data transfer can be assigned to any area

of the multi-channel RAM for each endpoint.

qBuffer area beginning address

The buffer area configuration register (address 0FED16) defines

the beginning address of the buffer area (every 32 bytes) for each

Endpoint. However, the only RAM area is configurable.

•00h [Address 000016], 01h [Address 002016]: Not configurable

•02h [Address 004016] to 1Fh [Address 03E016]: Configurable

qInterrupt-source dependant buffer area offset address

An offset value is added to the beginning address of each source,

which is specified by the interrupt source register (address

001D16), for each endpoint.

This section describes in detail the beginning address specified by

the buffer area set register as offset address 00h, according to

each endpoint.

(1) Endpoint 00

Endpoint 00 has two kinds of interrupt sources for accessing the

buffer. The respective address offsets are:

•BSRDY00 (SETUP Buffer Ready Interrupt): Offset address = 00h

•BRDY00 (OUT or IN Buffer Ready Interrupt):

Offset address = 08h

(2) Endpoint 01

The buffer area offset address for each interrupt source for of End-

point 01 varies according to the contents of the EP01 set register

(address 001916).

•In single buffer mode (DBLB01 = “0”):

Endpoint 01 has only one interrupt source for accessing the

buffer.

B0RDY01 (Buffer 0 Ready Interrupt): Offset address = 00h

•In double buffer mode (DBLB01 = “1”):

Endpoint 01 has two kinds of interrupt sources for accessing the

buffer.

B0RDY01 (Buffer 0 Ready Interrupt): Offset address = 00h

B1RDY01 (Buffer 1 Ready Interrupt):

The offset address varies according to the double buffer begin-

ning address set bit (BSIZ01).

-Offset address = 08h when BSIZ01 = 00

-Offset address = 10h when BSIZ01 = 01

-Offset address = 40h when BSIZ01 = 10

-Offset address = 80h when BSIZ01 = 11

(3) Endpoints 02 and 03

Same as Endpoint 01.

Notes

The selected RAM area must be within addresses 004016 to

03FF16.

Make sure the buffer area beginning address is set in agreement

with the offset address and the number of transmit/receive data

bytes.

This is particularly important when in the double buffer mode or

when handling 64-byte data.

Fig. 27 Example setting of buffer area beginning address

Fig. 28 Examples of interrupt source dependant buffer area offset address

0FED16 = 15h

000016

002016

004016

006016

02A016

03E016

Memory

SFR

RAM

0FED16

Disabled to be used

0000

0010 1010

(a) When selecting Endpoint 00

Memory

02A016

02A816

Offset

00h

08h

BSRDY00

BRDY00

02A016

00h

B0RDY01

02A016

032016

00h

80h

B0RDY01

B1RDY01

Memory

Offset

(b) When selecting Single Buffer Mode

Memory

Offset

(when BSIZ01 = 11)

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