p80c592ffa-00 NXP Semiconductors, p80c592ffa-00 Datasheet - Page 26

• Manufacturer Part Number: p80c592ffa-00
• Description: 8-bit Microcontroller With On-chip Can
• Manufacturer: NXP Semiconductors

1. User software should not write 1s to reserved bits. These bits may be used in future 8051 family products to invoke new features. In that
Philips Semiconductors
Dual DPTR
The dual DPTR structure (see Figure 17) is a way by which the chip
will specify the address of an external data memory location. There
are two 16-bit DPTR registers that address the external memory,
and a single bit called DPS = AUXR1/bit0 that allows the program
code to switch between them.
DPTR Instructions
The instructions that refer to DPTR refer to the data pointer that is
currently selected using the AUXR1/bit 0 register. The six
instructions that use the DPTR are as follows:
2002 Jan 15
80C51 8-bit microcontroller family
4K/8K/16K/32K Flash
case, the reset or inactive value of the new bit will be 0, and its active value will be 1. The value read from a reserved bit is indeterminate.
AUXR1
AUXR1
Symbol
GF2
DPS
—
BIT0
DPS
Address = A2H
Not Bit Addressable
Function
The GF2 bit is a general purpose user-defined flag. Note that bit 2 is not writable and is always read as a zero. This
allows the DPS bit to be quickly toggled simply by executing an INC AUXR1 instruction without affecting the GF2 bit.
DPS = AUXR1/bit0 = Switches between DPTR0 and DPTR1.
Select Reg
DPTR0
DPTR1
Not implemented, reserved for future use
(83H)
DPH
—
7
Figure 17.
(82H)
DPL
DPS
0
1
DPTR1
DPTR0
—
6
—
5
Figure 16. AUXR1: Auxiliary 1 Register
EXTERNAL
MEMORY
DATA
SU00745A
1
.
—
4
26
GF2
3
The data pointer can be accessed on a byte-by-byte basis by
specifying the low or high byte in an instruction which accesses the
SFRs. See application note AN458 for more details.
INC DPTR
MOV DPTR, #data16
MOV A, @ A+DPTR
MOVX A, @ DPTR
MOVX @ DPTR , A
JMP @ A + DPTR
New Register Name: AUXR1#
SFR Address: A2H
Reset Value: xxxx00x0B
2
0
89C51/89C52/89C54/89C58
—
1
Increments the data pointer by 1
Loads the DPTR with a 16-bit constant
Move code byte relative to DPTR to ACC
Move external RAM (16-bit address) to
ACC
Move ACC to external RAM (16-bit
address)
Jump indirect relative to DPTR
DPS
0
Reset Value = xxxx 00x0B
Product data
SU01561