PCA84C646 Philips Semiconductors, PCA84C646 Datasheet - Page 61

• Manufacturer Part Number: PCA84C646
• Description: Microcontrollers for TV tuning control and OSD applications
• Manufacturer: Philips Semiconductors

Philips Semiconductors
18 INPUT/OUTPUT
There are 3 different port options available for the port pins
in the 84CXXX derivatives (see Figs 47, 48 and 49).
Each I/O port line may be individually configured using one
of three mask options. The three I/O mask options are
specified below:
Option 1 Standard input/output with switched pull-up
Option 1 Input/output with Open drain output; this is
Option 2 Push-pull output; this is shown in Fig.49.
The state of each output port after a Power-on-reset can
also be selected using the mask options. All port mask
options are given in Section 19.1.
1995 Jun 15
handbook, full pagewidth
Microcontrollers for TV tuning
control and OSD applications
current source; this is shown in Fig.47.
shown in Fig.48.
write pulse
OUTL/ORL/ANL/MOV
data bus
Fig.47 Standard output with switched pull-up current source (Option 1).
ORL/ANL/MOV
D
Master
MQ
D
Slave
SQ
SQ
IN/MOV
61
The output stage consists of 4 transistors:
See Tables 41 and 42 for possible port option list.
TR1: N - channel transistor for ‘sink’
TR2: P - channel transistor for ‘boost-up’
TR3: P - channel transistor for ‘pull-up’
TR4: P - channel transistor for ‘constant current’.
TR2
TR1
V SS
PCA84C646; PCA84C846
TR3
100 A typical (V = 0.7 V
MED186 - 1
I/O port
line
O
V
DD
Preliminary specification
DD
)