p80cl580 NXP Semiconductors, p80cl580 Datasheet - Page 11

• Manufacturer Part Number: p80cl580
• Description: Low Voltage 8-bit Microcontrollers With Uart, I2c-bus And Adc
• Manufacturer: NXP Semiconductors

Philips Semiconductors
9
The P8xCL580 has 6 kbytes of Program Memory (ROM;
P83CL580 only) plus 256 bytes of Data Memory (RAM) on
board.The device has separate address spaces for
Program and Data Memory (see Fig.6). Using Port latches
P0 and P2, the P8xCL580 can address up to 128 kbytes of
external memory. The CPU generates both read (RD) and
write (WR) signals for external Data Memory accesses,
and the read strobe (PSEN) for external Program Memory.
9.1
The P83CL580 contains 6 kbytes of internal ROM. After
reset the CPU begins execution at location 0000H.
The lower 6 kbytes of Program Memory can be
implemented in either on-chip ROM or external Program
Memory.
If the EA pin is tied to V
from addresses 0000H to 17FFH are directed to the
internal ROM. Fetches from addresses 1800H to FFFFH
are directed to external ROM. Program Counter values
greater than 17FFH are automatically addressed to
external memory regardless of the state of the EA pin.
9.2
The P8xCL580 contains 256 bytes of internal RAM and
40 Special Function Registers (SFRs). Figure 6 shows the
internal Data Memory space divided into the lower
128 bytes, the upper 128 bytes, and the SFRs space.
Internal RAM locations 0 to 127 are directly and indirectly
addressable. Internal RAM locations 128 to 255 are only
indirectly addressable. The Special Function Register
locations 128 to 255 bytes are only directly addressable.
9.3
The upper 128 bytes are the address locations of the
SFRs. Figures 7 and 8 show the Special Function
Registers space. The SFRs include the port latches,
timers, peripheral control, serial I/O registers, etc. These
registers can only be accessed by direct addressing.
There are 128 directly addressable locations in the SFR
address space. Bit addressable SFRs are those that end
in 000B.
1997 Mar 14
Low voltage 8-bit microcontrollers with
UART, I
MEMORY ORGANIZATION
Program Memory
Data Memory
Special Function Registers (SFRs)
2
C-bus and ADC
DD
, then Program Memory fetches
11
halfpage
9.4
The P8xCL580 has five methods for addressing source
operands:
The first three methods can be used for addressing
destination operands. Most instructions have a
‘destination/source’ field that specifies the data type,
addressing methods and operands involved. For
operations other than MOVs, the destination operand is
also a source operand.
Register
Direct
Register-indirect
Immediate
Base-register plus index-register-indirect.
Addressing
Fig.5 The lower 128 bytes of internal RAM.
R7
R0
R7
R0
R7
R0
R7
R0
P80CL580; P83CL580
7FH
2FH
1FH
0FH
30H
20H
18H
17H
10H
08H
07H
0
MLA560 - 1
(bit addresses 0 to 7F)
4 banks of 8 registers
bit-addressable space
Product specification
(R0 to R7)