IS80LV51 Datasheet, PDF (9/43 Pages) Integrated Silicon Solution, Inc – CMOS SINGLE CHIP LOW VOLTAGE 8-BIT MICROCONTROLLER

IS80LV51
IS80LV31
ISSI ^®
SPECIAL FUNCTION REGISTERS
(Continued)
Stack Pointer (SP)
The Stack Pointer Register is eight bits wide. It is
incremented before data is stored during PUSH and
CALL executions. While the stack may reside anywhere
in on-chip RAM, the Stack Pointer is initialized to 07H after
a reset. This causes the stack to begin at location 08H.
Data Pointer (DPTR)
The Data Pointer consists of a high byte (DPH) and a low
byte (DPL). Its function is to hold a 16-bit address. It may
be manipulated as a 16-bit register or as two independent
8-bit registers.
Ports 0 To 3
P0, P1, P2, and P3 are the SFR latches of Ports 0, 1, 2,
and 3, respectively.
Serial Data Buffer (SBUF)
The Serial Data Buffer is actually two separate registers,
a transmit buffer and a receive buffer register. When data
is moved to SBUF, it goes to the transmit buffer, where it
is held for serial transmission. (Moving a byte to SBUF
initiates the transmission.) When data is moved from
SBUF, it comes from the receive buffer.
Timer Registers
Register pairs (TH0, TL0) and (TH1, TL1) are the 16-bit
Counter registers for Timer/Counters 0 and 1, respectively.
Control Registers
Special Function Registers IP, IE, TMOD, TCON, SCON,
and PCON contain control and status bits for the interrupt
system, the Timer/Counters, and the serial port. They are
described in later sections of this chapter.
Integrated Silicon Solution, Inc.
9
ADVANCE INFORMATION MC018-0A
10/01/98