1996 Dec 18

13

Philips Semiconductors

Product specification

8-bit microcontroller with DTMF generator,

256 bytes EEPROM and real-time clock

PCD3350A

7.1

EEPROM registers

7.1.1

The behaviour of the EEPROM and Timer 2 section is defined by the EEPROM Control Register, as detailed in Tables

9, 10 and 11.

Table 9

EEPROM Control Register, EPCR (address 04H, access type R/W)

Table 10 Description of EPCR bits

Table 11 Mode selection; X = don’t care

76543210

STT2

ET2I

T2F

EWP

MC3

MC2

MC1

0

BIT

SYMBOL

DESCRIPTION

7

STT2

Start T2. If STT2 = 0, then Timer 2 is stopped; T2 value held. If STT2 = 1, then T2

decrements from reload value.

6

ET2I

Enable T2 interrupt. If ET2I = 0, then T2F event cannot request interrupt. If ET2I = 1,

then T2F event can request interrupt.

5

T2F

Timer 2 flag. Set when T2 underflows (or by program); reset by program.

4

EWP

Erase or write in progress (EWP). Set by program (EWP starts EEPROM erase and/or

write and Timer 2). Reset at the end of EEPROM erase and/or write.

3

MC3

Mode control 3 to 1. These three bits in conjunction with bit EWP select the mode as

shown in Table 11.

2

MC2

1

MC1

0

−

This bit is set to a logic 0.

EWP

MC3

MC2

MC1

DESCRIPTION

0

0

0

0

read byte

0

0

1

0

increment mode

1

0

1

X

write page

1

1

0

0

erase/write page

1

1

1

1

erase page

X

0

0

1

not allowed

X1

0

1

X1

1

0