Maxim-integrated DS80C390 Manual do Utilizador descarregar pdf (Página 33)

DS80C390

33 of 58 110199

NOTES FOR DC ELECTRICAL CHARACTERISTICS:

1. Active current measured with 40 MHz clock source on XTAL1, V

=RST= 5.5 V, all other pins

disconnected.

2. Idle mode current measured with 40 MHz clock source on XTAL1, V

= 5.5 V, RST= EA =V

, all

other pins disconnected.

3. Stop mode current measured with XTAL1 = RST = EA = V

, V

= 5.5 V, all other pins

disconnected. This value is not guaranteed. Users who are sensitive to this specification should

contact Dallas Semiconductor for more information.

4. When these pins are used to address external memory or as CAN interface signals.

5. This measurement reflects the port during a 0 to 1 transition in I/O mode. During this period a one-

shot circuit drives the ports hard for two clock cycles.

6. Port 3 pins 3.6 and 3.7 will have a stronger than normal pullup drive for one oscillator period

following the transition of either the RD or WR from a 0 to 1 transition.

7. This is the current required from an external circuit to hold a logic low level on an I/O pin while the

corresponding port latch bit is set to 1. This is only the current required to hold the low level;

transitions from 1 to 0 on an I/O pin will also have to overcome the transition current.

8. Ports 1(in I/O mode), 3, 4, and 5 source transition current when being pulled down externally. It

reaches its maximum at approximately 2V.

9. During the external addressing mode, weak latches maintain the previously driven value from the

processor on Port 0 until such time that Port 0 is driven by external memory source; and on Port 1, 2

and 4 for one XTAL1 cycle prior to change in output address from Port 1, 2 and 4.

10. RST= V

. This condition mimics operation of pins in I/O mode.

TYPICAL I

VERSUS FREQUENCY

2 4 12 33 40 MHz

XTAL

FREQUENCY

1 2 ... 28 29 30 31 32 33 34 35 36 37 38 ... 57 58

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Maxim-integrated DS80C390 Manual do Utilizador Página 33