Universal Serial Bus (USB)
MPC885 PowerQUICC Family Reference Manual, Rev. 2
Freescale Semiconductor
31-9
controller for each token. Tokens are not checked for validity and are transmitted as is. The user is
responsible for token validity as well as CRC5 generation. Low speed transactions start with a preamble
which is generated by the USB host controller state machine when the LSP bit in the token TxBD is set.
The signalling on the USB lines is controlled by LSS in USMOD.
Figure 31-5. USB Controller Operating Modes
The SOF transaction is initiated and generated using a CPM timer and a microcode routine. Once the SOF
token is loaded to the host FIFO, it is transmitted as is.
When the TEST bit is programmed in the USMOD register, both the host state machine and the function
state machine are active. Endpoints 1-3 receive/transmit data according to tokens received from host. The
programming model and functional description are as described in
Section 31.11, “USB Function
Programming Model.”
reset
IDLE
setup
transmit
receive
SETUP
token
OUT
token
IN
token
PREAMBLE
Low Speed
Full
Speed
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 ...