CHAPTER 2 PIN FUNCTIONS
Preliminary User’s Manual A14874EJ3V0UM
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(11) EVINTLV6 to EVINTLV0 (output)
These are the interrupt vector output pins. They are connected to the EINTLV6 to EINTLV0 pins of the evaluation
chip.
2.2.12 Operation mode setting pins
The following pins are used to specify the operation mode of the NU85E.
The input level to these pins should remain fixed during NU85E operation. Do not change the input level to these
pins during operation.
(1) IFIROME (input)
This is the ROM area setting input pin. The setting is made according to the level input to the pin, as shown
below.
•
Low level: ROM connected as external memory (via VSB) is used
•
High level: ROM connected to VFB is used
When a low level is input to this pin, instruction processing begins after branching to the reset entry address of
the external memory, following the release of system reset. Instruction fetches and data access to the ROM
connected to VFB cannot be performed.
If a high level is input to this pin and a low level is input to the IFIROB2 pin, instruction processing begins after
branching to the reset entry address of the ROM connected to VFB, following the release of system reset. If a
high level is input to the IFIROB2 pin, instruction processing begins after branching to the reset entry address of
the external memory, following the release of system reset, however it is possible to access the area of ROM
connected to VFB that is allocated to addresses 100000H and higher.
(2) IFIROB2 (input)
This is the ROM area relocation setting input pin. It specifies the range for locating the ROM area.
The ROM area range is set as follows according to the input level to this pin.
•
Low level: Addresses 000000H to 0FFFFFH
•
High level: Addresses 100000H to 1FFFFFH
For details, see
3.4.1 (1) ROM relocation function
.
(3) IFIRA64, IFIRA32, IFIRA16 (input)
These are RAM area size selection input pins.
The RAM area size is set as follows according to the input level to these pins.
For details, see
3.4.2 RAM area
.
Table 2-8. IFIRA64, IFIRA32, and IFIRA16 Signals
IFIRA64
IFIRA32
IFIRA16
RAM Area Size
0
0
0
4 KB
0
0
1
12 KB
0
1
Arbitrary
28 KB
1
Arbitrary
Arbitrary
60 KB
Remark
0: low-level input 1: high-level input