Texas Instruments MSP50C614 1 RAM, 2 ROM, 3 I/O Pins, Port Description Function Name Address

Models: MSP50C614

1 414
Download 414 pages 24.44 Kb
Page 397
Image 397

Architecture

A.3.1 RAM

The MSP50C605 (like MSP50C614) has 640 17-bit words of internal data memory (static RAM). This RAM occupies a space extending from 0 to 0x27F in the address space.

A.3.2 ROM

The MSP50C605 contains 32K by 17-bit words of internal program ROM and 229,376 bytes by 8 bits (i.e., 1,835,008 bits) of slow data ROM. The program ROM space is divided into three areas:

1)The initial 2K words of ROM (0x0000 ± 0x07FF) is reserved for built in self- test (BIST) that is provided by Texas Instruments during mass production.

2)Customer can use the program ROM from address extending from 0x0800 to 0x7FFF. Restrictions on using certain program ROM location is shown in Figure A±2.

The Data ROM is a slower ROM dedicated only to hold data. Data ROM cannot execute program instructions. The Data ROM locations start from 0x00000 and ends at 0x37FFF. The lower 16 bits of the address to be read is provided into IO port DRA register (0x2C), the upper 2 bits goes into IO port DRP regis- ter (0x08). After 1.5 instruction cycle delay, the 8 bit data appears at IO port DRD (0x00). Discharging time is always 3 processor cycle and data is latched to port DRD during this time. There is 3.5 page in MSP50C605; pages 0, 1, and 2 are full; page 3 is half. Using 1Kbps MELP algorithm, this ROM can provide over 30 minutes of uninterrupted speech.

Port

Description

IO

Function

Name

Address

DRA

Data ROM Address

0x2C

write into this port to access 16 bit of

 

 

 

the data ROM address.

DRP

Data ROM Page

0x08

write into this port to select ROM page

DRD

Data ROM Data

0x00

read this port to get data at specified

 

 

 

ROM page and address

 

 

 

 

A.3.3 I/O Pins

The MSP50C605 has 32 input/output pins. 24 of the pins are software confi- gurable as either input or output (port C, D, and E). Eight of the pins are dedi- cated as input pins with programmable pullout resistors (port F). These ports are identical to the similar ports in MSP50C614, see Chapter 2 and Chapter 3 for details.

MSP50C605 Preliminary Data

A-3

Page 397
Image 397
Texas Instruments MSP50C614 manual 1 RAM, 2 ROM, 3 I/O Pins, Port Description Function Name Address