Intel® PXA255 Processor Developer’s Manual
9-23
I
2
C Bus Interface Unit
on the acknowledge pulse in receiver mode. After the processor reads the IDBR, the ACK/NAK
Control bit is written and the Transfer Byte bit is written, allowing the next byte transfer to proceed
to the I
2
C bus. The IDBR register is 0x00 after reset.
This is a read/write register. Ignore reads from reserved bits. Write zeros to reserved bits.
9.9.3
I
2
C Control Register (ICR)
The processor uses the ICR, shown in
Table 9-10
, to control the I
2
C unit.
This is a read/write register. Ignore reads from reserved bits. Write zeros to reserved bits.
Table 9-9. IDBR Bit Definitions
Physical Address
4030_1688
I
2
C Data Buffer Register
I
2
C Bus Interface Unit
Bit
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9
8
7
6
5
4
3
2
1
0
reserved
IDB
Reset 0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
31:8
—
reserved
7:0
IDB
I
2
C Data Buffer
: Buffer for I
2
C bus send/receive data.
Table 9-10. ICR Bit Definitions (Sheet 1 of 3)
Physical Address
4030_1690
I
2
C Control Register
I
2
C Bus Interface Unit
Bit
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9
8
7
6
5
4
3
2
1
0
reserved
FM
UR
SA
DIE
AL
D
IE
SS
DIE
BE
IE
IR
FIE
ITEIE
GC
D
IU
E
SCLE
MA
TB
AC
KN
AK
ST
O
P
ST
A
R
T
Reset 0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
31:16
—
reserved
15
FM
Fast Mode:
0 = 100 KBit/sec. operation
1 = 400 KBit/sec. operation
14
UR
Unit Reset
:
0 = No reset.
1 = Reset the I
2
C unit only.
13
SADIE
Slave Address Detected Interrupt Enable
:
0 = Disable interrupt.
1 = Enables the I
2
C unit to interrupt the
processor
when it detects a slave address match or
general call address.
12
ALDIE
Arbitration Loss Detected Interrupt Enable
:
0 = Disable interrupt.
1 = Enables the I
2
C unit to interrupt the processor when it loses arbitration in master mode.
11
SSDIE
Slave STOP Detected Interrupt Enable
:
0 = Disable interrupt.
1 = Enables the I
2
C unit to interrupt the processor
when it detects a STOP condition in
slave mode.
Summary of Contents for PXA255
Page 1: ...Intel PXA255 Processor Developer s Manual January 2004 Order Number 278693 002 ...
Page 24: ...xxiv Intel PXA255 Processor Developer s Manual Contents ...
Page 30: ...1 6 Intel PXA255 Processor Developer s Manual Introduction ...
Page 310: ...7 46 Intel PXA255 Processor Developer s Manual LCD Controller ...
Page 330: ...8 20 Intel PXA255 Processor Developer s Manual Synchronous Serial Port Controller ...
Page 358: ...9 28 Intel PXA255 Processor Developer s Manual I2 C Bus Interface Unit ...
Page 488: ...13 36 Intel PXA255 Processor Developer s Manual AC 97 Controller Unit ...
Page 572: ...16 30 Intel PXA255 Processor Developer s Manual Network SSP Serial Port ...
Page 599: ...Intel PXA255 Processor Developer s Manual 17 27 Hardware UART ...
Page 600: ......