P83CL781HDH View Datasheet(PDF) - Philips Electronics
Part Name
Description
MFG CO.
P83CL781HDH Datasheet PDF : 76 Pages
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Philips Semiconductors
Low voltage 8-bit microcontrollers with
UART and I2C-bus
Product specification
P83CL781; P83CL782
SYMBOL
PSEN
ALE
n.c.
EA
P0.7/AD7
P0.6/AD6
P0.5/AD5
P0.4/AD4
P0.3/AD3
P0.2/AD2
P0.1/AD1
P0.0/AD0
VDD
n.c.
PIN
DIP40 QFP44
DESCRIPTION
29
26 Program Store Enable: Read strobe to external Program Memory. When
executing code out of external Program Memory, PSEN is activated twice each
machine cycle. However, during each access to external Data Memory two
PSEN activations are skipped.
30
27 Address Latch Enable: Latches the low byte of the address during accesses to
external memory. It is activated every six oscillator periods and may be used for
external timing or clocking purposes.
−
28 Not connected.
31
29 External Access: When EA is held HIGH, the CPU executes out of the internal
Program Memory (unless the Program Counter exceeds 3FFFH). When EA is
held LOW, the CPU executes out of external Program Memory regardless of the
value of the program counter.
32
30 • Port 0: 8-bit open-drain bidirectional I/O port (P0.7 to P0.0). As an open-drain
33
31
output port it can sink/source 8 LS TTL loads. Port 0 pins that have logic 1s
34
32
written to them float, and in this state will function as high-impedance inputs.
35
33 • Low-order addressing: AD7 to AD0 provide the multiplexed low-order
address and data bus during accesses to external memory. In this application
36
34
the pins use the strong internal pull-ups when emitting logic 1s.
37
35
38
36
39
37
40
38 Power supply.
−
39 Not connected.
1997 Mar 14
10
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