PCD3359A 查看數據表（PDF） - Philips Electronics

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PCD3359A

8-bit microcontroller with DTMF generator and 128 bytes EEPROM

Philips Electronics 

Philips Semiconductors

8-bit microcontroller with DTMF

generator and 128 bytes EEPROM

Product specification

PCD3359A

7.1.2 EEPROM ADDRESS REGISTER (ADDR)

The EEPROM Address Register determines the EEPROM location to which an EEPROM access is directed.

As a whole, ADDR auto-increments after read and write cycles to EEPROM, but remains fixed after erase cycles. This

behaviour generates the correct ADDR contents for sequential read accesses and for sequential write or erase/write

accesses with intermediate page setup. Overflow of the 8-bit counter wraps around to zero.

Table 14 EEPROM Address Register, ADDR (address 01H, access type R/W)

7

6

5

4

3

2

1

0

0

AD6

AD5

AD4

AD3

AD2

AD1

AD0

Table 15 Description of ADDR bits

BIT

7

6 to 2

1 to 0

SYMBOL

DESCRIPTION

−

This bit is set to a logic 0.

AD6 to AD2 AD2 to AD6 select one of 32 pages.

AD1 to AD0

AD1 and AD0 are irrelevant during erase and write cycles. For read accesses, AD0 and

AD1 indicate the byte location within an EEPROM page. During page setup, finally, AD0

and AD1 select EEPROM Latch 0 to 3 whereas AD2 to AD6 are irrelevant. If increment

mode (Table 13) is active during page setup, the subcounter consisting of AD0 and AD1

increments after every write to an EEPROM latch, thus enhancing access to sequential

EEPROM latches. Incrementing stops when EEPROM Latch 3 is reached, i.e. when

AD0 and AD1 are both a logic 1.

7.1.3 EEPROM DATA REGISTER (DATR)

Table 16 EEPROM Data Register (address 03H; access type R/W)

7

6

5

4

3

2

1

0

D7

D6

D5

D4

D3

D2

D1

D0

Table 17 Description of DATR bits

BIT

7 to 0

SYMBOL

D7 to D0

DESCRIPTION

The EEPROM Data Register (DATR) is only a conceptual entity. A read operation from

DATR, reads out the EEPROM byte addressed by ADDR. On the other hand, a write

operation to DATR, loads data into the EEPROM latch (see Fig.5) defined by bits AD0

and AD1 of ADDR.

7.1.4 EEPROM TEST REGISTER (TST)

The EEPROM Test Register is used for testing purposes during device manufacture. It must not be accessed by the

device user.

7.2 EEPROM latches

The four EEPROM latches (EEPROM Latch 0 to 3; Fig.5) cannot be read by user software. Due to their construction, the

latches can only be preset, but not cleared. Successive write operations through DATR to the EEPROM latches actually

perform a logical OR with the previously stored data in EEPROM. The EEPROM latches are reset at the conclusion of

any EEPROM cycle.

1998 May 11

14

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