W90N740CDG Nuvoton Technology Corporation of America, W90N740CDG Datasheet - Page 64

• Manufacturer Part Number: W90N740CDG
• Description: IC MCU ARM7 TDMI 176-LQFP
• Manufacturer: Nuvoton Technology Corporation of America
• Series: W90r

Specifications of W90N740CDG

• Core Processor: ARM7
• Core Size: 16/32-Bit
• Speed: 80MHz
• Connectivity: EBI/EMI, Ethernet, UART/USART, USB
• Peripherals: DMA, POR, WDT
• Number Of I /o: 21
• Program Memory Type: ROMless
• Ram Size: 10K x 8
• Voltage - Supply (vcc/vdd): 1.62 V ~ 3.6 V
• Oscillator Type: External
• Operating Temperature: 0°C ~ 70°C
• Package / Case: 176-LQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Program Memory Size: -
• Data Converters: -

7.4.5
The W90N740 provides a write buffer to improve system performance. The write buffer can buffer up to
eight words of data. The write buffer may be enabled or be disabled via the WRBEN bit in the CAHCNF
register, and the buffer is disabled and flushed on reset.
To force data, which is in write buffer, to be written to external main memory. This operation is useful in
real time applications where the processor needs to be sure that a write to a peripheral has completed
before program execution continues.
To perform this command, you can set the DRWB and DCAH bits in CAHCON register.
Cache Control Registers Map
Cache Configuration Register (CAHCNF)
Cache controller has a configuration register to enable or disable the I-Cache, D-Cache, and Write
buffer.
WRBEN [2] ：Write buffer enable
When set to “1”, write buffer operation is enabled.
Write buffer is disabled after reset.
CAHCON
CAHADR
CAHCNF
CAHCNF
Register
Register
CTEST0
CTEST1
31
23
15
7
Drain write buffer
Write Buffer
0xFFF0.2000
0xFFF0.2004
0xFFF0.2008
0xFFF6.0000
0xFFF6.0004
0xFFF0.2000
Address
Address
30
22
14
6
RESERVED
29
21
13
5
R/W
R/W Cache configuration register
R/W Cache control register
R/W Cache address register
R/W Cache test register 0
R/W
R/W Cache configuration register
R
Cache test register 1
28
20
12
RESERVED
RESERVED
RESERVED
4
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W90N740CD/W90N740CDG
Description
Description
27
19
11
3
Publication Release Date: Aug. 18, 2005
WRBEN
26
18
10
2
DCAEN
25
17
9
1
0x0000.0000
0x0000.0000
0x0000.0000
0x0000.0000
0x0000.0000
Reset Value
0x0000.0000
Reset Value
Revision A6
ICAEN
24
16
8
0