LC66E516 View Datasheet(PDF) - SANYO -> Panasonic

Part Name

Description

Manufacturer

LC66E516

4-bit Single Chip Microcontroller with EPROM

SANYO -> Panasonic 

LC66E516

Usage notes

The LC66E516 single-chip IC is intended for use by those who are in charge of the development and evaluation of appli-

cation programs for the LC665XX series 4-bit single-chip microcontrollers. please keep in mind the following when the

user application developers are to work with this single-chip microcontroller.

• Notes on LC66E516 internal operations after reset

As the figure shows, the LC66E516 microcontroller starts normal

program execution at least 3 instruction cycles later after the oscil-

lation by the OSC function block becomes stable. In other words,

the RES pin level (active low) must be active for at least 3 instruc-

tion cycles after the oscillation becomes stabilized. As the figure

also shows, the oscillation stabilization requires more than 10 milli-

seconds. It is also shown that option data setting requires 8 instruc-

tion cycles after the RES pin level changes to the inactive level (or

to VIH voltage level). After all those operations are carried out, the

LC66E516 microcontroller starts program execution normally from

address 0 in the EPROM (that is, the content at address 0 is auto-

matically set in the program counter (PC)). At this point, Please

note that port output type will be open-drain, not pull-up output

type, as long as the RES pin stays active.

• Notes on evaluation of user application programs for the LC66506, LC66508, LC66512, LC66556, LC66558, LC66562,

microcontrollers

The above six mask programmed ROM-version microcontrollers are equipped with different ROMs in size from that of

the LC66E516 microcontroller. Therefore, the following things should be taken into consideration when you are to make

an access to the ROM on the LC66E516 microcontroller.

First, it should be kept in mind that the last 8 addresses between 3FF8 and 3FFF are used by the user in order to specify

functional option data. This 8-byte area is called option specification area. This option specification area must be exclu-

sively used for storing function option data. The option specification will be discussed in detail later in this catalog.

As far as the cross assembler to be employed is concerned, the user should use the one for the LC66516 microcontroller.

In addition, when you write your user application program, you cannot make any access to addresses beyond the area of

a mask programmed ROM. Such addresses cannot exist anywhere on mask programmed ROM-version microcontrollers.

To avoid such an illegal access to those nonexistent area, it is recommended that jump (or branch) operations with a JMP

instruction and so on be used in your user application program. Furthermore, please write "0" to the area beyond that of

a mask programmed ROM. In this case, needless to say, the last 8 addresses of the EPROM should be excluded from the

"0" padding.

When evaluating the LC66506, LC66508, LC66556, LC66558, do not use the SB instruction.

• Program protection from exposure to light

Exposure to light will destroy the precious EPROM data that you have entered with much labor. In order to protect them,

it should be strongly recommended that the EPROM window should be covered with an opaque label while you are at

work with the EPROM.

• For the LC66E516/P516, if the RES is set to "L" level during the HOLD mode (HOLD=L), be sure to change the HOLD

level from "L" to "H" and then change the RES level from "L" to "H" when releasing the HOLD mode.

No.2928–2/18

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