NEC PD754244 Manuel D’Utilisation
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
µ
PD754144
µ
PD754244
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).