Kindly plz give the answer to my question

The P89V51RD2 is an 80C51 microcontroller with 64 kB Flash and 1024 bytes of
data RAM.
A key feature of the P89V51RD2 is its X2 mode option. The design engineer can
choose to run the application with the conventional 80C51 clock rate (12 clocks per
machine cycle) or select the X2 mode (6 clocks per machine cycle) to achieve twice
the throughput at the same clock frequency. Another way to benefit from this feature
is to keep the same performance by reducing the clock frequency by half, thus
dramatically reducing the EMI.
The Flash program memory supports both parallel programming and in serial
In-System Programming (ISP). Parallel programming mode offers gang-programming
at high speed, reducing programming costs and time to market. ISP allows a device
to be reprogrammed in the end product under software control. The capability to
field/update the application firmware makes a wide range of applications possible.
The P89V51RD2 is also In-Application Programmable (IAP), allowing the Flash
program memory to be reconfigured even while the application is running.