Freescale Semiconductor MPC8260 - Manual (Page 1246)

FCC Transparent Controller
MPC8260 PowerQUICC II Family Reference Manual, Rev. 2
37-4 Freescale Semiconductor
Figure 37-2. Sending Transparent Frames between PowerQUICC IIs
PowerQUICC II(A) and PowerQUICC II(B) exchange transparent frames and synchronize each other
using RTS and CD. However, CTS is not required because transmission begins at any time. Thus, RTS is
connected directly to the other PowerQUICC II’s CD. GFMR[SYNL] is not used and transmission and
reception from each PowerQUICC II are independent.
RXD
CD
CLKx
TXD
RTS CD
RXD
BRGOx
RTS
TXD
CLKx BRGOx
BRGOx
Last Bit of Frame Data
First Bit of Frame Data
(Output is CLKx Input)
TXD
(Output is RXD Input)
RTS
(Output is CD Input)
or CRC
TxBD[L] = 1 Causes Negation of RTS
CD Lost Condition Terminates Reception of Frame
PowerQUICC II (A) PowerQUICC II (B)
Notes:
1
Each PowerQUICC II generates its own transmit clocks. If the transmit and receive clocks are the same, one can
generate transmit and receive clocks for the other PowerQUICC II. For example, CLKx on PowerQUICC II (B) could
be used to clock the transmitter and receiver
2 CTS should be configured as always asserted in the parallel I/O port or connected to ground externally.
3
The required GSMR configurations are DIAG= 00, CTSS=1, CTSP is a don’t care, CDS=1, CDP=0, TTX=1, and
TRX=1. REVD and TCRC are application-dependent.
4
The transparent frame contains a CRC if TxBD[TC] is set.