SNL310

16-Bit LCD Controller

:

:

:

:

0x000000

0x000001

0x000002

Byte1

0x000003

0x000004

0x000005

:

:

:

:

Byte2

Byte3

Byte4

Byte5

Byte6

Word 1

Word 2

ROM/Flash/SRAM

Read from

SNL310

:

:

:

:

0x000000

0x000001

0x000002

Byte1

0x000003

0x000004

0x000005

:

:

:

:

Byte2

Byte3

Byte4

Byte5

Byte6

Byte1

ROM/Flash/SRAM

Byte2

Read from

SNL310

Figure-6

Figure-5 shows the hardware connection for 8-bit/16-bit mode for external memory

accessing. The memory size calculation of each external memory device is a little

difference between 8-bit and 16-bit mode because of the address pin “A[22]”.

In 16-bit mode, “A[22]” pin can be connected to external memory. And chip will read

one byte data from external memory twice to get a complete 16-bit instruction code or

data. So the maximum memory size can support up to 64M bits of each device.

In 8-bit mode, considering the memory mapping issue, user can’t connected “A[22]”

pin to external memory. So the maximum memory size can support up to 32M bits.

Figure-6 figures out how the data be read from external memory in 8-bit/16-bit mode.

However, all the data access from external memory is treated as RAM accessing

except executes user’s program from external memory. User should use indirection

RAM access instruction to read data from external memory. Therefore, each chip

selects pin representing a RAM bank in memory allocation of SNL310.

Device No.

RAM bank

Start address

End Address

0x0080000

0x03FFFFF

0x0400000

0x07FFFFF

0x0800000

0x0BFFFFF

0x0C00000

0x0FFFFFF

Table-2 Addressing Capability (16-Bit Mode)

Ver: 1.7

May 2, 2003

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