User`s manual

3: INTERFACING TO THE PC CARD BUS
APPLICATION NOTES (S19A-G-005-05) EPSON 5-19
3.4.4 Register/Memory Mapping
The S1D13504 is a memory mapped device. The internal registers mapped in the lower PC Card
memory address space starting at zero. The display buffer requires 2M bytes and is mapped in the
third and fourth megabytes of the PC Card memory address space (ranging from 200000h to 3fffffh).
The PC Card socket provides 64M bytes of address space. Without further resolution on the decod-
ing logic (M/R# connected to A21), the entire register set is aliased for every 64 byte boundary
within the specified address range above. Since address bits A[25:22] are ignored, the S1D13504
registers and display buffer are aliased 16 times.
Note: If aliasing is not desirable, the upper addresses must be fully decoded.