Chapter 10. I
2
C Interface
10-11
I
2
C Register Descriptions
10.3.4 I
2
C Status Register (I2CSR)
The status register, shown in Figure 10-6, is read-only with the exception of the MIF and
MAL bits, which can be cleared by software. The MCF and RXAK bits are set at reset; all
other I2CSR bits are cleared on reset.
Figure 10-6. I
2
C Status Register (I2CSR)
3
TXAK
0
R/W
Transfer acknowledge. This bit specifies the value driven onto the SDA line during
acknowledge cycles for both master and slave receivers. The value of this bit
applies only when the I
2
C module is configured as a receiver, not a transmitter and
does not apply to address cycles; when the MPC8240 is addressed as a slave, an
acknowledge is always sent.
0 An acknowledge signal (low value on SDA) is sent out to the bus at the 9th clock
bit after receiving one byte of data.
1 No acknowledge signal response is sent (that is, acknowledge value on SDA is
high).
2
RSTA
0
W
Repeat START. Setting this bit causes a repeated START condition to be always
generated on the bus, provided the MPC8240 is the current bus master. Attempting
a repeated START at the wrong time (or if the bus is owned by another master)
results in loss of arbitration. Note that this bit is not readable.
0 No repeat START condition
1 Generates repeat START condition
1–0
—
00
R
Reserved
Table 10-6. I2CCR Field Descriptions—Offset 0x0_3008 (Continued)
Bits
Name
Reset
Value
R/W
Description
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
7
6
5
4
3
2
1
0
Reserved
MCF
MAAS
MBB
MAL
SRW
MIF
RXAK
Summary of Contents for MPC8240
Page 1: ...MPC8240UM D Rev 1 1 2001 MPC8240 Integrated Processor User s Manual ...
Page 38: ...xviii MPC8240 Integrated Processor User s Manual TABLES Table Number Title Page Number ...
Page 48: ...xlviii MPC8240 Integrated Processor User s Manual Acronyms and Abbreviations ...
Page 312: ...6 94 MPC8240 Integrated Processor User s Manual ROM Flash Interface Operation ...
Page 348: ...7 36 MPC8240 Integrated Processor User s Manual PCI Host and Agent Modes ...
Page 372: ...8 24 MPC8240 Integrated Processor User s Manual DMA Register Descriptions ...
Page 394: ...9 22 MPC8240 Integrated Processor User s Manual I2O Interface ...
Page 412: ...10 18 MPC8240 Integrated Processor User s Manual Programming Guidelines ...
Page 454: ...12 14 MPC8240 Integrated Processor User s Manual Internal Arbitration ...
Page 466: ...13 12 MPC8240 Integrated Processor User s Manual Exception Latencies ...
Page 516: ...16 14 Watchpoint Trigger Applications ...
Page 538: ...B 16 MPC8240 Integrated Processor User s Manual Setting the Endian Mode of Operation ...
Page 546: ...C 8 MPC8240 Integrated Processor User s Manual ...
Page 640: ...INDEX Index 16 MPC8240 Integrated Processor User s Manual ...