UPD75218 NEC, UPD75218 Datasheet - Page 23

• Manufacturer Part Number: UPD75218
• Description: 4-BIT SINGLE-CHIP MICROCOMPUTER
• Manufacturer: NEC

5.8
Caution The FIP controller/driver can only operate at the high and intermediate speeds (PCC = 0011B or 0010B)
The FIP controller/driver in the PD75218 has the same functions as that in its predecessor, PD75216A:
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The FIP controller/driver outputs the segment signal by automatically reading display data (DMA operation)
and automatically generates the digit signal.
The FIP controller/driver can control the FIP of 9 to 16 segments and 9 to 16 digits with the display mode register
(DSPM) and the digit select register (DIGS) (within the range of up to 26 display outputs).
The display outputs unused for dynamic display can be used as static outputs.
The dimmer function provides eight levels of intensity.
Such hardware is contained that a key scan application is possible.
• A key scan interrupt (IRQKS) is caused. (A key scan timing is detected.)
• Key scan data can be output from key scan registers (KS0 and KS1) onto a segment output pin.
A high-voltage output pin (40 V) is provided which can directly drive the FIP.
• Pins dedicated to segments (S0 to S9): V
• Digit output pins (T0 to T15): V
A mask option enables a pull-down resistor to be incorporated for each bit.
FIP CONTROLLER/DRIVER
of the main system clock (SCC.0 = 0). It may cause errors with any other clock or in the standby mode.
Thus, be sure to stop FIP controller operation (DSPM.3 = 0) and then shift the unit to any other clock mode
or the standby mode.
Segment data latch (16)
Key scan registers
(KS0 and KS1)
S0-S9
10
10
Display data memory
(64
12
4 bits)
Output buffer with a high withstand voltage
Fig. 5-8 FIP Controller/Driver Block Diagram
T15/S10
and T14/S11
OD
2
= 40 V, I
2
2
2
T13/S12/PH0-
T10/S15/PH3
4
Selector
4
Selector
OD
Internal bus
Port H
OD
= 40 V, I
4
4
= 15 mA
4
4
4
OD
Display
mode
register
= 3 mA
4
T0-T9
10
10
Digit
select
register
Digit signal
generator
4
Dimmer
select
register
4
V
LOAD
Key scan
flag (KSF)
V
PRE
IRQKS
generation
signal
PD75218
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