W78E516DDG Datasheet, PDF (11/90 Pages) Nuvotem Talema – 8-BIT MICROCONTROLLER

W78E516D/W78E058D Data Sheet
7 FUNCTIONAL DESCRIPTION
The W78E516D/W78E058D series architecture consists of a core controller surrounded by various
registers, four general purpose I/O ports, one special purpose programmable 4-bits I/O port, 512 bytes
of RAM, three timer/counters, a serial port. The processor supports 111 different op-codes and refer-
ences both a 64K program address space and a 64 K data storage space.
7.1 On-Chip Flash EPROM
The W78E516D/W78E058D series includes one 64K/32K bytes of main FLASH EPROM for applica-
tion program (APROM) and one 4K bytes of FLASH EPROM for loader program (LDROM) when op-
erating the in-system programming feature. In normal operation, the microcontroller will execute the
code from the 64K/32K bytes of main FLASH EPROM. By setting program registers, user can force
microcontroller to switch to the programming mode which microcontroller will execute the code (loader
program) from the 4K bytes of auxiliary FLASH EPROM, and this loader program is going to update
the contents of the 64K/32K bytes of main FLASH EPROM. After reset, the microcontroller executes
the new application program in the main FLASH EPROM. This in-system programming feature makes
the job easy and efficient in which the application needs to update firmware frequently. In some appli-
cations, the in-system programming feature make it possible that the end-user is able to easily update
the system firmware by the them without opening the chassis.
7.2 I/O Ports
The W78E516D/W78E058D series has four 8-bit ports and one extra 4-bit port. Port 0 can be used as
an Address/Data bus when external program is running or external memory/device is accessed by
MOVC or MOVX instruction. In these cases, it has strong pull-ups and pull-downs, and does not need
any external pull-ups. Otherwise it can be used as a general I/O port with open-drain circuit. Port 2 is
used chiefly as the upper 8-bits of the Address bus when port 0 is used as an address/data bus. It also
has strong pull-ups and pull-downs when it serves as an address bus. Port1 and 3 act as I/O ports
with alternate functions. Port 4 is only available on PLCC/QFP/LQFP package type. It serves as a
general purpose I/O port as Port 1 and Port 3. Another bit-addressable bidirectional I/O port P4. P4.3
and P4.2 are alternative function pins. It can be used as general I/O port or external interrupt input
sources ( INT2 / INT3 ).
7.3 Serial I/O
The W78E516D/W78E058D series have one serial port that is functionally similar to the serial port of
the original 8032 family. However the serial port on the W78E516D/W78E058D series can operate in
different modes in order to obtain timing similarity as well.
7.4 Timers
Timers 0, 1, and 2 each consist of two 8-bit data registers. These are called TL0 and TH0 for Timer 0,
TL1 and TH1 for Timer 1, and TL2 and TH2 for Timer 2. The TCON and TMOD registers provide con-
trol functions for timers 0 and 1. The T2CON register provides control functions for Timer 2. RCAP2H
and RCAP2L are used as reload/capture registers for Timer 2.
The operations of Timer 0 and Timer 1 are the same as in the 8051 CPU. Timer 2 is a special feature
of the W78E516D/W78E058D series: it is a 16-bit timer/counter that is configured and controlled by
the T2CON register. Like Timers 0 and 1, Timer 2 can operate as either an external event counter or
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Publication Release Date: Feb 15, 2011
Revision A09