PC87570 datasheet(18/168 Pages) NSC

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Introduction

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1.3.3

DEV Environment

DEV environment is most commonly used to develop soft-

ware on Application Development Boards (ADBs) and In-

System Emulators (ISEs). In this environment, the develop-

ment tools can load code and data of up to 64 Kbytes to off-

chip RAM. This can replace the Base Memory used in

IRE/IRD environment (on-chip/off-chip boot-code). The de-

velopment tool can also load code and data of up to 56

Kbytes to off-chip RAM (application).

In this environment, the pins of ports PF, PG and PH are al-

located for the interface to the Base Memory, for ISE inter-

rupt and for CR16A core status indication. The system may

re-gain these ports using the I/O Expansion protocol and

off-chip logic, while maintaining cycle-by-cycle and binary

compatibility with the IRE environment. Using the same soft-

ware, this environment is binary and cycle-by-cycle compati-

ble with IRD and IRE environments. All features of IRE

environment can be implemented either directly or by using

additional external logic. Figure 1-3 shows a system in DEV

environment.

Clock

External

Memory

PC87570

32KX1/32KCLKIN

32KX2

HMR

HA18-0

HD7-0

HIOR

HIOW

IRQ1

IRQ11

IRQ12

WR1-0

SEL0

A18-16, A15-0

D15-8

AD7-0

DA3-0

PA6-0

PB7-0

PC7-0

PD7-0

HIOCHRDY

RTC

Battery

VBAT

IRQ8

Crystal

32.768 KHz

External Keyboard

Internal

Keyboard

KBSOUT15-0

KBSIN7-0

SRAM or

Flash

ENV0

GA20

AVCC

AGND

VCC

GND

Power

Supply

SCL

D7-0

HMEMRD

HMEMWR

PG4-0

PE1-0

PF7-0

PH5-0

HMEMCS

HAEN

EXINT0,10,11,15

PFAIL

RING

SHBM

HRMS

Conﬁguration

Inputs

I/O

Expansion

HDEN

TRIS

HPWRON

PC0

External Mouse

Auxiliary PS/2

Interface

HRSTO

SELIO

(Matrix)

SDA

SWIN

Analog

Reset

Control

(power-up reset)

GPIO

Interrupt

ACCESS.bus

System

Timers

ENV1

Figure 1-3. DEV Environment

SEL1

(Application)

VREF

ADC

DAC

Off-chip

Base

(Boot code

SRAM)

Memory

Restored

Ports

* Optional 8/16 data bus

VCC

CLK

ISE

BST2-0

PFS

PLI

Development

Support

BE1,0

CBRD

PC87570 数据表(PDF) 18 Page - National Semiconductor (TI)

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