I
2
C Controller
MPC885 PowerQUICC Family Reference Manual, Rev. 2
32-10
Freescale Semiconductor
Figure 32-11
shows the RFCR/TFCR bit fields.
Table 32-7
describes the RFCR/TFCR bit fields.
0x14
RTEMP
Word
Rx temp. Reserved for CPM use.
0x18
TSTATE
Word
Tx internal state. Reserved for CPM use.
0x1C
TPTR
Word
Tx internal data pointer
2
is updated by the SDMA channels to show the next address
in the buffer to be accessed.
0x20
TBPTR
Hword TxBD pointer. Points to the next descriptor that the transmitter transfers data from
when it is in an idle state or to the current descriptor during frame transmission. After
a reset or when the end of the descriptor table is reached, the CPM initializes TBPTR
to the value in TBASE. Most applications should not write TBPTR, but it can be
modified when the transmitter is disabled or when no transmit buffer is used.
0x22
TCOUNT Hword Tx internal byte count
2
is a down-count value initialized with TxBD[Data Length] and
decremented with every byte read by the SDMA channels.
0x24
TTEMP
Word
Tx temp. Reserved for CP use.
0x28-0x2F
—
—
Used for I
2
C/SPI
relocation, see
Section 18.7.3, “Parameter RAM
.”
1
As programmed in I2C_BASE. The default value is IMMR + 0x3C80. See
Section 18.7.3, “Parameter RAM
.”
2
Normally, these parameters need not be accessed.
0
2
3
4
5
7
Field
—
BO
AT[1–3]
Reset
0000_0000
R/W
R/W
Addr
I2C Base + 04 (RFCR)/I2C Base + 05 (TFCR)
Figure 32-11. I
2
C Function Code Registers (RFCR/TFCR)
Table 32-7. RFCR/TFCR Field Descriptions
Bits
Name
Description
0–2
—
Reserved, should be cleared.
3–4
BO
Byte ordering. Set BO to select the required byte ordering for the buffer. If BO is changed on the fly,
it takes effect at the beginning of the next frame (Ethernet, HDLC, and transparent) or at the
beginning of the next BD. See
Appendix A, “Byte Ordering.”
00 Reserved
01 Modified little-endian.
1x Big-endian or true little-endian.
5–7
AT[1–3]
Address type 1–3. Contains the user-defined function code value used during the SDMA channel
memory access. AT0 is always driven high to identify this channel access as a DMA-type access.
Table 32-6. I
2
C Parameter RAM Memory Map (continued)
Offset
1
Name
Width
Description
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 ...