YLCDRSK2378 Renesas Electronics America, YLCDRSK2378 Datasheet - Page 447

• Manufacturer Part Number: YLCDRSK2378
• Description: KIT DEV EVAL H8S/2378 LCD
• Manufacturer: Renesas Electronics America
• Series: H8®r

Specifications of YLCDRSK2378

• Main Purpose: Displays, LCD Controller
• Embedded: Yes, MCU, 16-Bit
• Utilized Ic / Part: YLCDRSK2378
• Primary Attributes: 5.7" QVGA, Touch Screen
• Secondary Attributes: Source Code on CD, Debugging Requires Emulator Cable E10A USB/JTAG
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

8.4.3
Auto Request Mode: In auto request mode, transfer request signals are automatically generated
within the EXDMAC in cases where a transfer request signal is not issued from outside, such as in
transfer between two memories, or between a peripheral module that is not capable of generating
transfer requests and memory. In auto request mode, transfer is started when the EDA bit is set to
1 in EDMDR.
In auto request mode, either cycle steal mode or burst mode can be selected as the bus mode.
Block transfer mode cannot be used.
External Request Mode: In external request mode, transfer is started by a transfer request signal
(EDREQ) from a device external to this LSI. DMA transfer is started when EDREQ is input while
DMA transfer is enabled (EDA = 1).
The transfer request source need not be the data transfer source or data transfer destination.
The transfer request signal is accepted via the EDREQ pin. Either falling edge sensing or low level
sensing can be selected for the EDREQ pin by means of the EDREQS bit in EDMDR (low level
sensing when EDREQS = 0, falling edge sensing when EDREQS = 1).
Setting the EDRAKE bit to 1 in EDMDR enables a signal confirming transfer request acceptance
to be output from the EDRAK pin. The EDRAK signal is output when acceptance and transfer
processing has been started in response to a single external request. The EDRAK signal enables
the external device to determine the timing of EDREQ signal negation, and makes it possible to
provide handshaking between the transfer request source and the EXDMAC.
In external request mode, block transfer mode can be used instead of burst mode. Block transfer
mode allows continuous execution (burst operation) of the specified number of transfers (the block
size) in response to a single transfer request. In block transfer mode, the EDRAK signal is output
only once for a one-block transfer, since the transfer request via the EDREQ pin is for a block
unit.
8.4.4
There are two bus modes: cycle steal mode and burst mode. When the activation source is an auto
request, either cycle steal mode or burst mode can be selected. When the activation source is an
external request, cycle steal mode is used.
Cycle Steal Mode: In cycle steal mode, the EXDMAC releases the bus at the end of each transfer
of a transfer unit (byte, word, or block). If there is a subsequent transfer request, the EXDMAC
DMA Transfer Requests
Bus Modes
Rev.7.00 Mar. 18, 2009 page 379 of 1136
Section 8 EXDMA Controller (EXDMAC)
REJ09B0109-0700