M451
May. 4, 2018
Page
345
of
1006
Rev.2.08
M4
51
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NICA
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mapped external device (for Bank0/EBI_nCS0) to 0x6000_0000 ~ 0x6003_FFFF, 0x6004_0000 ~
0x6007_FFFF, 0x6008_0000 ~ 0x600B_FFFF and 0x600C_0000 ~ 0x600F_FFFF
simultaneously.
EBI Data Width Connection - Address Bus and Data Bus Multiplex Mode
6.5.5.2
The EBI supports device whose address bus and data bus are multiplexed. For the external
device with separated address and data bus, the connection to device needs additional latch
device to latch the address. In this case, pin EBI_ALE is connected to the latch device to latch the
address value. Pin EBI_AD is the input of the latch device, and the output of the latch device is
connected to the address of external device.
For 16-bit device, the EBI_AD [15:0] shared by address and 16-bit data, EBI_ADR [18:16] is
dedicated for address and could be connected to 16-bit device directly. The EBI_ADR[19] will be
ignore when EBI data width is set as 16-bit width. For 8-bit device, only EBI_AD [7:0] shared by
address and 8-bit data, EBI_AD[15:8] and EBI_ADR[19:16] is dedicated for address and could be
connected to 8-bit device directly. Figure 6.5-2 shows the connection of 16-bit data width device
and Figure 6.5-3 show the connection of 8-bit data width device.
Addr[15:0]
nCS
nOE
Data[15:0]
nWE
EBI_nCS
EBI_nRD
EBI_AD[15:0]
EBI_nWR
External Bus Interface
1M x 16-bit
SRAM
Address
latch device
EBI_ALE
EBI_AD[15:0]
En
D
Q
EBI_ADR[18:16]
Addr[18:16]
Figure 6.5-2 Connection of 16-bit EBI Data Width with 16-bit Device
