MEC1322 datasheet(117/456 Pages) MICROCHIP

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 2014 - 2015 Microchip Technology Inc.

DS00001719D-page 117

MEC1322

9.8.1

EMBEDDED MEMORY MAP

Each Embedded Memory interface provides direct access for the Host into two windows in the EC 32-bit internal

address space. This mapping is shown in Figure 9-3, "Embedded Memory Addressing":

FIGURE 9-3:

EMBEDDED MEMORY ADDRESSING

The Base addresses, the Read limits and the Write limits are defined by registers that are in the EC address space and

cannot be accessed by the Host. In each region, the Read limit need not be greater than the Write limit. The regions

can be contiguous or overlapping. For example, if the Region 0 Read limit is set to 0 and the Write limit is set to a positive

number, then the Embedded Memory interface defines a region in the EC memory that the EC can read and write but

is write-only for the host. This might be useful for storage of security data, which the Host might wish to send to the EC

but should not be readable in the event a virus invades the Host.

Each window into the EC memory can be as large as 32k bytes in the 32-bit internal address space. See FIGURE 8-1:

Memory Layout on page 113 for host accessible regions.

32-bit internal address

space

0000_0000h

FFFF_FFFFh

Region_0_Base_Address

Region_0_Write_Limit

Region_0_Read_Limit

Host Read/Write

Host Read Only

No Host Access

Region_1_Base_Address

Region_1_Write_Limit

Region_1_Read_Limit

Host Read/Write

Host Read Only

No Host Access

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