Datasheet

Section 1 Overview
Page 4 of 1384 R01UH0310EJ0500 Rev. 5.00
Sep 25, 2012
H8S/2426, H8S/2426R, H8S/2424 Group
Type
Module/
Function Description
EXDMA
controller
(EXDMAC)
• DMA transfer is possible on two channels
• Two activation sources (auto-request and external request)
• Two transfer modes (normal mode and block transfer mode)
• Dual address mode or single address mode can be selected
• 16-Mbyte address space can be specified directly
• Repeat area can be set
Note: * EXDMAC is supported only by the H8S/2426 Group and
H8S/2426R Group.
DMA
Data
transfer
controller
(DTC)
• Transfer is possible on any number of channels
• An interrupt source can trigger data transfer (chain transfer is
possible)
• Three transfer modes (normal mode, repeat mode, and block
transfer mode)
• Byte or word can be set as the transfer unit
• Activation by software is possible
External
bus
extension
Bus
controller
(BSC)
• External address space: 16 Mbytes
• Manages the external address space divided into eight areas
Chip select signals (CS0 to CS7) can be output
8-bit access or 16-bit access can be selected
2-state access or 3-state access can be selected
Program wait states can be inserted
• External memory interfaces (burst ROM, DRAM*
1
, synchronous
DRAM*
2
, address/data multiplexed I/O)
• Bus arbitration function (bus arbitration of the bus masters CPU,
DTC, DMAC, and EXDMAC)
Notes: 1. DRAM is not supported in the 5-V version.
2. EXDMAC is supported only by the H8S/2426 Group and
H8S/2426R Group.