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Chapter 10 mask options, 1 pin mask options, 1 mask option of p70/kr4 to p73/kr7 – NEC PD754144 User Manual

Page 233: 2 reset# pin mask option, 2 oscillation stabilization wait time mask option

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233

User’s Manual U10676EJ3V0UM

CHAPTER 10 MASK OPTIONS

The

µPD754144 and 754244 have the following mask options.

Table 10-1. Selection of Mask Options

Item

µPD754144

µPD754244

P70/KR4 to P73/KR7

On-chip pull-up resistors specifiable in 1-bit units by mask option

RESET pin

On-chip pull-up resistors specifiable by mask option

Oscillation stabilization wait time

Fixed to 56/f

CC

Selectable from 2

17

/f

X

and 2

15

/f

X

10.1 Pin Mask Options

10.1.1 Mask option of P70/KR4 to P73/KR7

On-chip 100 k

Ω (typ.) pull-up resistors can be specified by mask option for P70/KR4 to P73/KR7 (port 7).

The mask option can be specified in 1-bit units.

10.1.2 RESET pin mask option

On-chip 100 k

Ω (typ.) pull-up resistors can be specified by mask option for the RESET pin.

10.2 Oscillation Stabilization Wait Time Mask Option

The oscillation stabilization wait time mask option differs between the

µPD754144 and 754244.

In the

µPD754244, it is possible to select a wait time by mask option. This wait time refers to the time after the

standby function is released by the RESET signal until the system returns to the normal operation mode (refer to 8.2

Releasing Standby Mode, for details.)

The wait time can be selected from the following two times.

(1) 2

17

/f

X

(21.8 ms: at f

X

= 6.0 MHz, 31.3 ms: at f

X

= 4.19 MHz)

(2) 2

15

/f

X

(5.46 ms: at f

X

= 6.0 MHz, 7.81 ms: at f

X

= 4.19 MHz)

The

µPD754144 has no mask option and the wait time is fixed to 56/f

CC

(56

µs at 1.0 MHz).

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