W78E58B Winbond, W78E58B Datasheet - Page 4

• Manufacturer Part Number: W78E58B
• Description: 8 BIT MICROCONTROLLER
• Manufacturer: Winbond

5. BLOCK DIAGRAM
6. FUNCTIONAL DESCRIPTION
The W78E58B 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 opcodes and references both a 64K
program address space and a 64K data storage space.
RAM
The internal data RAM in the W78E58B is 512 bytes. It is divided into two banks: 256 bytes of
scratchpad RAM and 256 bytes of AUX-RAM. These RAMs are addressed by different ways.
P1.0
P1.7
RAM 0H
are R0 and R1 of the selected register bank.
RAM 80H
R1 of the selected registers bank.
P3.0
P3.7
P4.0
P4.3
Port
1
Port
Port
3
4
7FH can be addressed directly and indirectly as the same as in 8051. Address pointers
FFH can only be addressed indirectly as the same as in 8051. Address pointers are R0,
Interrupt
UART
Port 1
Port 3
Port 4
Timer
Timer
Timer
Latch
Latch
Latch
2
0
1
XTAL1
Oscillator
XTAL2
PSW
Bus & Clock
Instruction
Sequencer
Controller
Decoder
ALE
ACC
&
T1
PSEN
ALU
Reset Block
RAM & SFR
SFR RAM
Address
512 bytes
- 4 -
RST
T2
B
Pointer
Stack
Power control
VCC
Vss
Temp Reg.
Addr. Reg.
Incrementor
DPTR
PC
Port 0
Latch
32KB
ROM
ROM
4KB
Port 2
Latch
W78E58B
Port
Port
2
0
P0.0
P2.0
P2.7
P0.7