NuMicro® NUC029LEE/NUC029SEE
32-bit Arm
®
Cortex
®
-M0 Microcontroller
Aug, 2018
Page
166
of
497
Rev 1.00
N
U
MICRO
®
N
UC02
9L
E
E
/N
UC029
S
E
E
T
E
CHN
ICA
L R
E
F
E
R
E
NC
E
M
A
NU
A
L
For 16-bit device, the AD [15:0] shared by address (Addr [15:0]) and 16-bit data (Data [15:0]). For
8-bit device, only AD [7:0] shared by address (Addr [7:0]) and 8-bit data (Data [7:0]), AD [15:8] is
dedicated for address (Addr [15:8]) and could be connected to 8-bit device directly.
Addr[15:0]
nCS
nOE
Data[15:0]
nWE
nCS
nRE
AD[15:0]
nWE
External Bus Interface
64K x 16-bit
SRAM
Address
latch device
ALE
AD[15:0]
En
D
Q
Figure 6.5-2 Connection of 16-bit EBI Data Width with 16-bit Device
Addr[7:0]
nCS
nOE
Data[7:0]
nWE
nCS
nRE
AD[7:0]
nWE
External Bus Interface
64K x 8-bit
SRAM
Address
latch device
ALE
AD[7:0]
En
D
Q
AD[7:0]
AD[15:8]
Addr[15:8]
Figure 6.5-3 Connection of 8-bit EBI Data Width with 8-bit Device
When the system access data width is larger than EBI data width (8-bit / 16 bit data width), the
EBI controller will finish a system access command by operating EBI access more than once. For
example, if system requests a 32-bit data through EBI device, the EBI controller will operate
accessing four times when setting EBI data width with 8-bit data width.
6.5.4.3 EBI Operating Control
MCLK Control
In the chip, all EBI signals will be synchronized by MCLK when EBI is operating. When the chip
connects to the external device with slower operating frequency, the MCLK can divide most to 32