83C145 Datasheet, PDF (8/40 Pages) NXP Semiconductors – Microcontrollers for TV and video MTV

Philips Semiconductors
Microcontrollers for TV and video (MTV)
Product specification
83C145; 83C845
83C055; 87C055
7 DESCRIPTION OF STANDARD FUNCTIONS
For a description of the standard functions please refer to
the “Data Handbook IC20; Section 2: 80C51 Technical
Description” .
8 INPUT/OUTPUT (I/O)
The I/O structure of the 83C055 is similar to the standard
I/O structure in the 80C51, except for the points described
in Table 5.
9 DESCRIPTION OF DERIVATIVE FUNCTIONS
9.1 General description
Although the 83C055 is specifically referred to throughout
this data sheet, the information applies to all the devices.
The differences to 80C51 features and the derivative
functions are described in the following Sections and
Chapters.
Figure 1 shows the block diagram of the 83C055.
9.1.1 NOT IMPLEMENTED FUNCTIONS
Standard functions to the 80C51 that are not implemented
in the 83C055:
• As Data and Program Memory are not externally
expandable on the 83C055, the ALE, EA, and
PSEN signals are not implemented.
• Idle mode.
• Power-down mode.
9.1.2 INTERRUPT FACILITIES DIFFERENCES
The interrupt facilities of the 83C055 differ from those of
the 80C51 as follows:
• The IP register is not used, and the IE register (address
A8H) is similar to that on the 80C51;see Table 36.
• The VSYNC input used by the OSD facility can generate
an interrupt. The active polarity of the pulse is
programmable (see Section 13.7); interrupt occurs at
the leading edge of the pulse.
• Since there is no serial port, there are no interrupts nor
control bits relating to this interrupt. The interrupts and
their vector addresses are shown in Table 3.
• External Interrupt 1 is modified so that an interrupt is
generated when the input switches are in either direction
(on the 80C51, there is a programmable choice between
interrupt on a negative edge or a LOW level on INT1).
This facility allows for software pulse-width
measurement handling of a remote control.
Table 3 Program Memory address
EVENT
Reset
External INT0
Timer 0
External INT1
Timer 1
VSync Start
PROGRAM MEMORY ADDRESS
000H
003H
00BH
013H
01BH
023H
9.1.3 PCON REGISTER DIFFERENCE
The PCON register format is shown in Table 4. Bits GF1
and GF0 are general purpose flag bits.
Table 4 PCON Register format (address 87H)
7
6
5
4
3
2
1
0
−
−
−
− GF1 GF0 −
−
9.1.4 I/O PORTS DIFFERENCES
Table 5 I/O ports differences
I/O
Port 0
Port 1
Port 2
Port 3
STANDARD 80C51
83C055
external memory expansion
8-bit open-drain bidirectional port; and includes:
alternative use for PWM outputs
8-bit general purpose quasi-bidirectional
4-bit open-drain port, and includes alternative uses
for analog inputs and a PWM output
quasi-bidirectional and can be used for external
memory expansion
open-drain and general purpose
quasi-bidirectional; all eight bits have alternate uses 3 port bits have some of the same alternative uses
as on the 80C51 but not necessarily on the same
pins; 5 pins are open-drain and general purpose
1996 Mar 22
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