676
11100B–ATARM–31-Jul-12
SAM4S Series [Preliminary]
Figure 32-11. Master Write with One, Two or Three Bytes Internal Address and One Data Byte
Figure 32-12. Master Read with One, Two or Three Bytes Internal Address and One Data Byte
32.8.6.2
10-bit Slave Addressing
For a slave address higher than 7 bits, the user must configure the address size (IADRSZ) and
set the other slave address bits in the internal address register (TWI_IADR). The two remaining
Internal address bytes, IADR[15:8] and IADR[23:16] can be used the same as in 7-bit Slave
Addressing.
Example: Address a 10-bit device (10-bit device address is b1 b2 b3 b4 b5 b6 b7 b8 b9 b10)
1.
Program IADRSZ = 1,
2.
Program DADR with 1 1 1 1 0 b1 b2 (b1 is the MSB of the 10-bit address, b2, etc.)
3.
Program TWI_IADR with b3 b4 b5 b6 b7 b8 b9 b10 (b10 is the LSB of the 10-bit
address)
below shows a byte write to an Atmel AT24LC512 EEPROM. This demonstrates
the use of internal addresses to access the device.
Figure 32-13. Internal Address Usage
S
DADR
W
A
IADR(23:16)
A
IADR(15:8)
A
IADR(7:0)
A
DATA
A
P
S
DADR
W
A
IADR(15:8)
A
IADR(7:0)
A
P
DATA
A
A
IADR(7:0)
A
P
DATA
A
S
DADR
W
TWD
Three bytes internal address
Two bytes internal address
One byte internal address
TWD
TWD
S
DADR
W
A
IADR(23:16)
A
IADR(15:8)
A
IADR(7:0)
A
S
DADR
W
A
IADR(15:8)
A
IADR(7:0)
A
A
IADR(7:0)
A
S
DADR
W
DATA
N
P
Sr
DADR
R
A
Sr
DADR
R
A
DATA
N
P
Sr
DADR
R
A
DATA
N
P
TWD
TWD
TWD
Three bytes internal address
Two bytes internal address
One byte internal address
S
T
A
R
T
M
S
B
Device
Address
0
L
S
B
R
/
W
A
C
K
M
S
B
W
R
I
T
E
A
C
K
A
C
K
L
S
B
A
C
K
FIRST
WORD ADDRESS
SECOND
WORD ADDRESS
DATA
S
T
O
P
Содержание SAM4S Series
Страница 44: ...44 11100B ATARM 31 Jul 12 SAM4S Series Preliminary ...
Страница 412: ...412 11100B ATARM 31 Jul 12 SAM4S Series Preliminary ...
Страница 1105: ...1105 11100B ATARM 31 Jul 12 SAM4S Series Preliminary ...
Страница 1142: ...1142 11100B ATARM 31 Jul 12 SAM4S Series Preliminary Figure 43 3 100 ball VFBGA Package Drawing ...
Страница 1143: ...1143 11100B ATARM 31 Jul 12 SAM4S Series Preliminary Figure 43 4 64 lead LQFP Package Drawing ...
Страница 1145: ...1145 11100B ATARM 31 Jul 12 SAM4S Series Preliminary Figure 43 5 64 lead QFN Package Drawing ...