HD6412350 Hitachi, HD6412350 Datasheet - Page 139

• Manufacturer Part Number: HD6412350
• Description: (HD6412350 / HD6432351) 16-BIT MICROCONTROLLER
• Manufacturer: Hitachi

6.1
The H8S/2350 Series has a built-in bus controller (BSC) that manages the external address space
divided into eight areas. The bus specifications, such as bus width and number of access states,
can be set independently for each area, enabling multiple memories to be connected easily.
The bus controller also has a bus arbitration function, and controls the operation of the internal bus
masters: the CPU, DMA controller (DMAC), and data transfer controller (DTC).
6.1.1
The features of the bus controller are listed below.
Manages external address space in area units
Basic bus interface
DRAM interface
Burst ROM interface
In advanced mode, manages the external space as 8 areas of 2-Mbytes
In normal mode, manages the external space as a single area
Bus specifications can be set independently for each area
DRAM/burst ROM interfaces can be set
Chip select (CS0 to CS7) can be output for areas 0 to 7
8-bit access or 16-bit access can be selected for each area
2-state access or 3-state access can be selected for each area
Program wait states can be inserted for each area
DRAM interface can be set for areas 2 to 5 (in advanced mode)
Row address/column address multiplexed output (8/9/10 bits)
Two byte access methods (2-CAS)
Burst operation (fast page mode)
T
Choice of CAS-before-RAS refreshing or self-refreshing
Burst ROM interface can be set for area 0
Choice of 1- or 2-state burst access
P
Overview
Features
cycle insertion to secure RAS precharging time
Section 6 Bus Controller
119