IS80LV52 Datasheet, PDF (20/48 Pages) Integrated Silicon Solution, Inc – CMOS SINGLE CHIP LOW VOLTAGE 8-BIT MICROCONTROLLER

IS80LV52
IS80LV32
Timer/Counter 2 Set-Up
Except for the baud rate generator mode, the values given
for T2C0N do not include the setting of the TR2 bit.
Therefore, bit TR2 must be set separately to turn the
Timer on.
Table 7. Timer/Counter 2 Used as a Timer
Mode
T2CON
Internal External
Control⁽¹⁾ Control⁽²⁾
16-Bit Auto-Reload
00H
08H
16-Bit Capture
01H
09H
Baud Rate Generator Receive 34H
36H
and Transmit Same Baud Rate
Receive Only
24H
26H
Transmit Only
14H
16H
Table 8. Timer/Counter 2 Used as a Counter
Mode
TMOD
Internal External
Control⁽¹⁾ Control⁽²⁾
16-Bit Auto-Reload
02H
0AH
16-Bit Capture
03H
0BH
Notes:
1. Capture/Reload occurs only on Timer/Counter overflow.
2. Capture/Reload occurs on Timer/Counter overflow and a 1 to
0 transition on T2EX (P1.1) pin except when Timer 2 is used
in the baud rate generating mode.
ISSI ^®
SERIAL INTERFACE
The Serial port is full duplex, which means it can transmit
and receive simultaneously. It is also receive-buffered,
which means it can begin receiving a second byte before
a previously received byte has been read from the receive
register. (However, if the first byte still has not been read
when reception of the second byte is complete, one of the
bytes will be lost.) The serial port receive and transmit
registers are both accessed at Special Function Register
SBUF. Writing to SBUF loads the transmit register, and
reading SBUF accesses a physically separate receive
register.
The serial port can operate in the following four modes:
Mode 0:
Serial data enters and exits through RXD. TXD outputs
the shift clock. Eight data bits are transmitted/received,
with the LSB first. The baud rate is fixed at 1/12 the
oscillator frequency (see Figure 15).
Mode 1:
Ten bits are transmitted (through TXD) or received (through
RXD): a start bit (0), eight data bits (LSB first), and a stop
bit (1). On receive, the stop bit goes into RB8 in Special
Function Register SCON. The baud rate is variable (see
Figure 16).
Mode 2:
Eleven bits are transmitted (through TXD) or received
(through RXD): a start bit (0), eight data bits (LSB first), a
programmable ninth data bit, and a stop bit (1). On transmit,
the ninth data bit (TB8 in SCON) can be assigned the value
of 0 or 1. Or, for example, the parity bit (P, in the PSW) can
be moved into TB8. On receive, the ninth data bit goes into
RB8 in Special Function Register SCON, while the stop bit
is ignored. The baud rate is programmable to either 1/32 or
1/64 the oscillator frequency (see Figure 17).
Mode 3:
Eleven bits are transmitted (through TXD) or received
(through RXD): a start bit (0), eight data bits (LSB first), a
programmable ninth data bit, and a stop bit (1). In fact,
Mode 3 is the same as Mode 2 in all respects except the
baud rate, which is variable in Mode 3 (see Figure 18).
In all four modes, transmission is initiated by any instruction
that uses SBUF as a destination register. Reception is
initiated in Mode 0 by the condition RI = 0 and REN = 1.
Reception is initiated in the other modes by the incoming
start bit if REN = 1.
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Integrated Silicon Solution, Inc. — 1-800-379-4774
ADVANCE INFORMATION MC019-0A
10/01/98