EAGLE
PRELIMINARY
Ver 1.3
3.27.10.3 TWI Address Register(TWIADDR)
Address : FFE0 AC08h
Bit
31 : 8
7 : 0
R/W
R
R/W
Description
Default Value
Reserved.
Slave Address.
-
00h
7-bit slave address represent TWI address.
[7:1] = Slave Address
[ 0] = Not mapped
3.27.10.4 TWI Data Register ( TWIDATA)
Address : FFE0 AC0Ch
Bit
31 : 8
7: 0
R/W
R
R/W
Description
Default Value
Reserved.
8 bits data to transfer
-
00h
3.27.10.5 TWI Baud-rate 0 Register (TWIBR0 )
Address : FFE0 AC10h
Bit
31 : 8
7: 0
R/W
R
R/W
Description
Reserved.
Baud-rate 0 Value. (larger than 3)
Default Value
-
00h
3.27.10.6 TWI Baud-rate 1 Register (TWIBR1)
Address : FFE0 AC14h
Bit
31 : 9
8 : 0
R/W
R
R/W
Description
Reserved.
Baud-rate 1 Value. (larger than 0)
Default Value
-
000h
TWIBR0 = fbus × 700ns + 3
fbus
SCL =
(2TWIBR1+ TWIBR0 + 7)
*
= AMBA APB clock frequency (system clock frequency divided by two)
fbus
*SCL = TWI bit rate
ex) When APB clock is 50MHz, bps of TWI is 400 Kbps (
= 50MHz , SCL = 400Kbps)
fbus
TWIBR0 = 50MHz×700ns + 3 = 50×106 ×700×10−9 + 3 = 38
50MHz
50×106
(2TWIBR1+ 45)
fbus
SCL =
⇒ 400Kbps =
⇒ 400×103 =
(2TWIBR1+TWIBR0 + 7)
(2TWIBR1+ 38+ 7)
Beijing Peak Microtech Co.Ltd.
CONFIDENTIAL
204
ETC [ ETC ]
