NEC PD750008 - Manual (Page 255)

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CHAPTER 10 MASK OPTION
CHAPTER 10 MASK OPTION
10.1 PIN
The pins of the µPD750008 have the following mask options:
Table 10-1. Selecting Mask Option of Pin
Pin Mask Option
P40-P43 Pull-up resistor can be connected in 1-bit units.
P50-P53
P40 through P43 (port 4) or P50 through P53 (port 5) can be connected with pull-up resistors by mask option.
The mask option can be specified in 1-bit units.
If the pull-up resistor is connected by mask option, port 4 or 5 goes high on reset. If the pull-up resistor
is not connected, the port goes into a high-impedance state on reset.
The ports of the µPD75P0016 do not have a mask option and is always open.
10.2 MASK OPTION OF STANDBY FUNCTION
The standby function of the µPD750008 allows you to select wait time by using a mask option. The wait
time is required for the CPU to return to the normal operation mode after the standby function has been
released by the RESET signal (for details, see Section 7.2).
The following two wait times can be selected:
<1> 2 17 /f
X
(21.8 ms at f
X
= 6.00 MHz, 31.3 ms at f
X
= 4.19 MHz)
<2> 2 15 /f
X
(5.46 ms at f
X
= 6.00 MHz, 7.81 ms at f
X
= 4.19 MHz)
The µPD75P0016 does not have a mask option and its wait time is fixed to 2 15 /f
X
.
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