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4 nmi signal mask function, 5 bus interface pin – NEC V850/SV1 User Manual

Page 29

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CHAPTER 4 CAUTIONS

User’s Manual U14337EJ1V0UM00

29

4.4

NMI Signal Mask Function

When using the P00/NMI pin in the port mode, do not mask the NMI signal.

4.5

Bus Interface Pin

The operation of the pin for the bus interface differs between the emulator and the target device as follows.

Table 4-1. Bus Interface Pin Operation List (1/2)

(a) During break

Internal Memory

External Memory

Memory Used by

Emulator

Internal

ROM

Internal RAM

Internal

Peripheral I/O

Emulation RAM

Target System

Pin Name

F

R

W

R

R

W

R

W

R

W

R

W

A16 to A21

Hold the last accessed address

Active

Active

AD0 to AD15

Hi-Z

Active

Active

ASTB

H

Active

Active

R/W

H

Active

Active

DSTB

H

H

Active

LBEN

H

Active

Active

UBEN

H

Active

Active

WAIT

Invalid

Maskable

Maskable

HLDRQ

Maskable

Maskable

Maskable

HLDAK

H or L

H or L

H or L

WRL

H

H

H

Note

WRH

H

H

H

Note

RD

H

H

Note

H

Note Active

Remarks 1. F:

Fetch

R:

Read

W:

Write

2. H:

High-level output

L:

Low-level output

Hi-Z:

High-impedance