ATMEga64L ATMEL Corporation, ATMEga64L Datasheet - Page 25

• Manufacturer Part Number: ATMEga64L
• Description: 8-bit AVR Microcontroller with 64K Bytes In-System Programmable Flash
• Manufacturer: ATMEL Corporation

External Memory
Interface
Overview
2490G–AVR–03/04
With all the features that the External Memory Interface provides, it is well suited to
operate as an interface to memory devices such as external SRAM and Flash, and
peripherals such as LCD-display, A/D, and D/A. The main features are:
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When the eXternal MEMory (XMEM) is enabled, address space outside the internal
SRAM becomes available using the dedicated external memory pins (see Figure 1 on
page 2, Table 27 on page 71, Table 33 on page 75, and Table 45 on page 83). The
memory configuration is shown in Figure 11.
Figure 11. External Memory with Sector Select
Note:
External Memory
(0-60K x 8)
Four different wait-state settings (Including no wait-state).
Independent wait-state setting for different external memory sectors (configurable
sector size).
The number of bits dedicated to address high byte is selectable.
Bus Keepers on data lines to minimize current consumption (optional).
1. ATmega64 in non ATmega103 compatibility mode: Memory Configuration A is avail-
able (Memory Configuration B N/A).
ATmega64 in mega103 compatibility mode: Memory Configuration B is available
(Memory Configuration A N/A).
Memory Configuration A
Internal Memory
Lower Sector
Upper Sector
SRW01
SRW00
SRW11
SRW10
0x0000
0x10FF
0x1100
0xFFFF
SRL[2..0]
External Memory
(1)
(0-60K x 8)
Memory Configuration B
ATmega64(L)
Internal Memory
SRW10
0x0000
0x0FFF
0x1000
0xFFFF
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