I
2
C Controller
MPC885 PowerQUICC Family Reference Manual, Rev. 2
32-8
Freescale Semiconductor
bit masks the corresponding interrupt. Unmasked I2CER bits must be cleared before the CPM clears
internal interrupt requests.
Figure 32-9
shows both registers.
This registers are affected by HRESET and SRESET.
Table 32-4
describes the I2CER/I2CMR fields.
32.4.5
I
2
C Command Register (I2COM)
The I
2
C command register, shown in
Figure 32-10
, is used to start I
2
C transfers and to select master or
slave mode.
This register is affected by HRESET and SRESET.
Table 32-5
describes I2COM fields.
0
2
3
4
5
6
7
Field
—
TXE
—
BSY
TXB
RXB
Reset
0000_0000
R/W
R/W
Addr
0x870(I2CER)/0x874 (I2CMR)
Figure 32-9. I
2
C Event/Mask Registers (I2CER/I2CMR)
Table 32-4. I2CER/I2CMR Field Descriptions
Bits
Name
Description
0–2
—
Reserved and should be cleared.
3
TXE
Tx error. Set when an error occurs during transmission.
4
—
Reserved and should be cleared.
5
BSY
Busy. Set after the first character is received but discarded because no Rx buffer is available.
6
TXB
Tx buffer. Set when the Tx data of the last character in the buffer has been sent.
7
RXB
Rx buffer. Set after the last character is written to the Rx buffer and the RxBD is closed.
0
1
6
7
Field
STR
—
M/S
Reset
0000_0000
R/W
R/W
Addr
0x86C
Figure 32-10. I
2
C Command Register (I2COM)
Table 32-5. I2COM Field Descriptions
Bits
Name Description
0
STR
Start transmit. In master mode, setting STR causes the I
2
C controller to start sending data from the
I
2
C Tx buffers if they are ready. In slave mode, setting STR when the I
2
C controller is idle causes it
to load the Tx data register from the current Tx buffer (if ready) and start sending when it receives
an address byte that matches the slave address with R/W = 1. STR is always read as a 0.
Summary of Contents for PowerQUICC MPC870
Page 98: ...MPC885 PowerQUICC Family Reference Manual Rev 2 I 4 Freescale Semiconductor ...
Page 118: ...MPC885 Overview MPC885 PowerQUICC Family Reference Manual Rev 2 1 20 Freescale Semiconductor ...
Page 158: ...The MPC8xx Core MPC885 PowerQUICC Family Reference Manual Rev 2 3 18 Freescale Semiconductor ...
Page 288: ...MPC885 PowerQUICC Family Reference Manual Rev 2 III 4 Freescale Semiconductor ...
Page 554: ...MPC885 PowerQUICC Family Reference Manual Rev 2 V 6 Freescale Semiconductor ...
Page 1090: ...UTOPIA Interface MPC885 PowerQUICC Family Reference Manual Rev 2 43 8 Freescale Semiconductor ...
Page 1312: ...Byte Ordering MPC885 PowerQUICC Family Reference Manual Rev 2 A 8 Freescale Semiconductor ...
Page 1336: ...MPC885 PowerQUICC Family Reference Manual Rev 2 D 16 Freescale Semiconductor ...
Page 1358: ...MPC885 PowerQUICC Family Reference Manual Rev 2 D 38 Freescale Semiconductor ...
Page 1370: ...MPC880 MPC885 PowerQUICC Family Reference Manual Rev 2 E 4 Freescale Semiconductor ...
Page 1386: ...Revision History MPC885 PowerQUICC Family Reference Manual Rev 2 I 2 Freescale Semiconductor ...