HD6417021 Hitachi Semiconductor, HD6417021 Datasheet - Page 64

• Manufacturer Part Number: HD6417021
• Description: SuperH RISC engine
• Manufacturer: Hitachi Semiconductor

3.1
The SH7020 and SH7021 operate in one of four operating modes (modes 0, 1, 2, and 7). Modes 0
and 1 differ in the bus width of memory area 0. The mode is selected by the mode pins (MD2–
MD0) as indicated in table 3.1. Do not change the mode selection while the chip is operating.
Table 3.1
Operating Mode
Mode 0*
Mode 1*
Mode 2
Mode 7*
Notes : 1.SH7021 PROM version only
3.2
3.2.1
In mode 0, memory area 0 has an eight-bit bus width. For the memory map, see section 8, Bus
State Controller.
3.2.2
In mode 1, memory area 0 has a 16-bit bus width.
3.2.3
In mode 2, memory area 0 is assigned to the on-chip ROM.
3.2.4
Mode 7 is a PROM mode. In this mode, the EPROM can be programmed.For details,see section
16, ROM. Do not set to mode 7 unless the product is the SH7021(PROM version).
2.Only modes 0 and 1are available in the SH7020 ROMless version.
2
2
Types of Operating Modes and Their Selection
Operating Mode Descriptions
Mode 0 (MCU Mode 0)
Mode 1 (MCU Mode 1)
Mode 2 (MCU Mode 2)
Mode 7 (PROM Mode)
Operating Mode Selection
MD2
0
0
0
1
Section 3 Operating Modes
Pin Settings
MD1
0
0
1
1
MD0
0
1
0
1
Mode Name
MCU mode 0
MCU mode 1
MCU mode 2
PROM mode
Bus Width of Area 0
8 bits
16 bits
On-chip ROM
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