WorksheetsUNIT-III TIMER /COUNTER & SERIAL COMMUNICATION
Total questions: 40
Worksheet time: 20mins
TMOD is a ___ bit register.
a) 8 bit
b) 16 bit
c) 32 bit
d) 4 bit
Which port of the 8051 is used ONLY as a bidirectional I/O port?
a) Port 0
b)Port 1
c)Port 2
d)Port 3
Which register holds the serial data during transmission?
a)TH0
b)TMOD
c)SBUF
d)IE
In counter mode, what does the timer count?
a)External events on pins T0/T1
b)Internal clock pulses
c)Instruction cycles
d)Program counter values
The IE and IP registers are
a) Only bit addressable register
b) Only byte addressable register
c) Bit and byte addressable registers
d) None of the above
The highest priority interrupt in 8051 is
a)Timer 0
b)External INT1
c)Serial port
d)External INT0
How many interrupt sources are there in 8051?
4
5
6
8
The TMOD register in 8051 is used to:
a) Control the serial port
b) Select timer mode of operation
c) Enable external interrupts
d) Configure I/O ports
In TCON, bits TF0 and TF1 are:
a) Reset bits
b) Timer overflow flags for Timer 0 and Timer 1
c) Serial communication flags
d) External interrupt flags
In SCON, bit RI (Receive Interrupt flag) is set when:
a) Parity bit is set
b) Data is received into SBUF
c) Timer 1 overflows
d) Data is transmitted from SBUF
Which register stores overflow flag of Timer 0?
a)TH0
b)TL0
c)TCON
d)SCON
RS232C is a
a) Parallel interface standard
b) Programmable peripheral interface
c) Serial interface standard
d) None of the above
The frequency of 8051 timer is
a) fosc
b) fosc/24
c) fosc/12
d) fosc/2
The byte addresses of port 0 and port 1 are
a) 80H and 90H
b) 80H and AOH
c) 90H and AOH
d) AOH and BOH
TMOD is a
a) Only bit addressable register
b) Bit and byte addressable register
c) Only byte addressable register
d) None of the above
The TCON register in 8051 is mainly used for:
a) Selecting mode of timers
b) Enabling RAM
c)Configuring serial communication
d) Controlling timer start/stop and interrupts
Which SFR is used to set interrupt priority?
a)TMOD
b)IP
c)IE
d)SCON
The maximum frequency of 8051 counter is
a) fosc/24
b) fosc/2
c) fosc/12
d) fosc
The full form of UART is
a)Universal Asynchronous Receiver Transmitter
b)Unified Automatic Receiver Transmitter
c)Universal Addressable Register Transfer
d)Universal Active Register Transmitter
Which SFR is used for serial communication?
a)SCON
b)TCON
c)TMOD
d)IE
If TMOD = 01H, which mode is selected?
a)Timer 0, mode 1
b)Timer 1, mode 0
c)Timer 0, mode 2
d)Timer 1, mode 1
The EA bit of IE register is used to
a) Enable/disable all interrupts
b) Disable all interrupts
c) Set all interrupts
d) Reset all interrupts
RS232 standard is used for
a)Parallel data communication
b)Serial data communication
c)Wireless communication
d)I²C communication
If M1=1 and M0=0 the operating mode is called as
a) 13 bit Timer
b) 16 bit Timer
c) 8 bit auto reload timer
d) Split Timer
Microcontroller 8051 contains
a) Only one timer/counter
b) 3 timer/counters
c) 2 timer/counters
d) 4 timer/counters
What is the bit address range for I/O ports in 8051?
a)00H–7FH
b)80H–FFH
c)20H–2FH
d)00H–FFH
How many ports are available in 8051?
2
3
4
5
0013H is the vector address of lll
a) Exterior interrupt 0
b) Timer interrupt 0
c) Timer interrupt 1
d) External interrupt 1
What is the size of each timer register in 8051?
a)8-bit
b)32-bit
c)12-bit
d)16-bit
A student needs to toggle P1.0 every 1000 machine cycles. Which peripheral will he use?
a)Serial port
b)Interrupt
c)Timer
d)Port0
SCON is a ___ bit register.
a)4-bit
b) 6-bit
c) 8-bit
d) 16-bit
Which register is used to enable/disable interrupts?
a)TCON
b)IE
c)IP
d)TMOD
RS-232C is a standard interface for connecting
a) Hard disk and CPU
b) Printer and Memory
c) Data Terminal Equipment (DTE) and Data Communication Equipment (DCE)
d) RAM and ROM
In PCON, bit SMOD is used to:
a) Select timer mode
b) Enable interrupts
c) Enter power-down mode
d) Double the baud rate of serial communication
The serial communication of 8051 contains
a) 2 modes
b) 3 modes
c) 5 modes
d) 4 modes
RS-232C is used in which type of communication?
a) Parallel communication
b) Serial communication
c) Wireless communication
d) Optical communication
Which of the following ports of 8051 is used as a dual-purpose port?
a)P0 and P2
b)P1 only
c)P3 only
d)P0,P2 and P3
Timer 0 in mode 2 operates as
a)13-bit timer
b)Event counter
c)16-bit timer
d)8-bit auto-reload timer
Which pin of 8051 is used for serial transmission?
a)P3.0
b)P3.1
c)P1.0
d)P2.0
Which SFR is used to control timer modes in 8051?
a)TCON
b)TMOD
c)TH0
d)TL1
