AP1639

The AP1639 is one member of the in-system programming of C164 OTP devices that provides 64 KByte OTP memory on-chip. And the the C164CI OTP module is a 512 KBit memory organized as 16K double words of 32 bit each. On its CPU interface it presents a fast read access (60ns @ fCPU = 25 MHz) of 32 bit in one machine cycle. Read accesses of code and data are possible in any addressing mode, thus realizing the highest CPU performance with fetch and execution of double word instructions in a single instruction cycle.

In order to access the on-chip OTP memory after booting from external memory the internal OTP memory must be enabled via software by setting bit ROMEN in register SYSCON. The lower 32 KBytes of the OTP memory can be mapped to segment 0 or segment 1, controlled by bit ROMS1 in register SYSCON. Mapping to segment 1 preserves the external memory containing the startup code, while mapping to segment 0 replaces the lower 32 KBytes of the external memory with onchip OTP memory. In this case a valid vector table must be provided. If you want to know more information such as the electrical characteristics about the AP1639, please download the datasheet in www.seekic.com or www.chinaicmart.com .