The erase time is 100±5% ms. This is independent of processor clock speed. You can erase one sector in 100 ms, or you can erase multiple sectors in the same time. Hence, a complete chip erase can be done in 100ms.
Programming time is 1.0±5% ms per Flash page (256 bytes). The programming time is given for writing 256 bytes from RAM to the flash. Data must be written to the flash in blocks of 256 bytes.