Low-Power LCD Microcontroller

16

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In-Application Programming

The in-application programming feature allows the

microcontroller to modify its own flash program memory

while simultaneously executing its application software.

This allows on-the-fly software updates in mission-

critical applications that cannot afford downtime.

Alternatively, it allows the application to develop cus-

tom loader software that can operate under the control

of the application software. The utility ROM contains

user-accessible flash programming functions that erase

and program flash memory. These functions are

described in detail in the user’s guide supplement for

this device.

Register Set

Most functions of the device are controlled by sets of reg-

isters. These registers provide a working space for mem-

ory operations as well as configuring and addressing

peripheral registers on the device. Registers are divided

into two major types: system registers and peripheral reg-

isters. The common register set, also known as the sys-

tem registers, includes the ALU, accumulator registers,

data pointers, interrupt vectors and control, and stack

pointer. The peripheral registers define additional func-

tionality that may be included by different products based

on the MAXQ architecture. This functionality is broken up

into discrete modules so that only the features required

for a given product need to be included. Tables 1 and 4

show the MAXQ2000 register set.

Table 1. System Register Map

MODULE NAME (BASE SPECIFIER)

REGISTER

INDEX

AP (8h)

A (9h)

PFX (Bh)

IP (Ch)

SP (Dh)

DPC (Eh)

DP (Fh)

0xh

AP

A[0]

PFX

IP

——

—

1xh

APC

A[1]

——

SP

——

2xh

—

A[2]

——

IV

——

3xh

—

A[3]

—

—

—

Offs

DP0

4xh

PSF

A[4]

——

—

DPC

—

5xh

IC

A[5]

——

—

GR

—

6xh

IMR

A[6]

——

LC0

GRL

—

7xh

—

A[7]

——

LC1

BP

DP1

8xh

SC

A[8]

——

—

GRS

—

9xh

—

A[9]

—

—

—

GRH

—

Axh

—

A[10]

——

—

GRXL

—

Bxh

IIR

A[11]

——

—

FP

—

Cxh

—

A[12]

——

——

—

Dxh

—

A[13]

——

——

—

Exh

CKCN

A[14]

——

——

—

Fxh

WDCN

A[15]

——

——

—

Note: Names that appear in italics indicate that all bits of a register are read-only. Names that appear in bold indicate that a register

is 16 bits wide. Registers in module AP are bit addressable.