W78E054D Datasheet, PDF (12/89 Pages) List of Unclassifed Manufacturers – 8-bit microcontroller

W78E054D/W78E052D Data Sheet
7 FUNCTIONAL DESCRIPTION
The W78E054D/W78E052D series architecture consists of a core controller surrounded by various
registers, five general purpose I/O ports, 16K/8K flash EPROM, 2K FLASH EPROM for ISP function,
256 bytes of RAM, three timer/counters, and a serial port. The processor supports 111 different op-
codes and references both a 64K program address space and a 64K data storage space.
7.1 On-Chip Flash EPROM
The W78E054D/W78E052D series include one 16K/8K bytes of main Flash EPROM for application
program.
7.2 I/O Ports
The W78E054D/W78E052D 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/PQFP/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 W78E054D/W78E052D series have one serial port that is functionally similar to the serial port of
the original 8032 family. However the serial port on the W78E054D/W78E052D 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 W78E054D/W78E052D: 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 as
an internal timer, depending on the setting of bit C/T2 in T2CON. Timer 2 has three operating modes:
capture, auto-reload, and baud rate generator. The clock speed at capture or auto-reload mode is the
same as that of Timers 0 and 1.
7.5 Interrupts
The Interrupt structure in the W78E054D/W78E052D is slightly different from that of the standard
8052. Due to the presence of additional features and peripherals, the number of interrupt sources and
vectors has been increased. The W78E054D/W78E052D provides 8 interrupt resources with four pri-
ority level, including four external interrupt sources, three timer interrupts, serial I/O interrupts.
7.6 Data Pointers
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Publication Release Date: Jun 9, 2015
Revision A13