Circuit Board Reference Manual

MCF548x Reference Manual, Rev. 3
29-26 Freescale Semiconductor
29.2.3.7 USB Transmitted Packet Counter Register (TXPCNT)
29.2.3.8 USB Counter Overflow Register (CNTOVR)
The CNTOVR tracks overflow of each of the counter registers described above. When a counter overflow
occurs, the appropriate bit in this register is set, and the USBAISR[CTROVFL] bit is set. Writing to any
of the counters will result in the corresponding overflow bit being cleared as well.
1514131211109876543210
R TXPCNT
W
Reset0000000000000000
Reg
Addr
MBAR + 0xB08C
Figure 29-24. USB Transmitted Packet Counter Register (TXPCNT)
Table 29-24. TXPCNT Field Descriptions
Bits Name Description
15–0 TXPCNT Transmitted packet counter. This register counts the number of packets transmitted by the
USB.
76543210
R0 TXP
CNT
FRME
CNT
PIDE
CNT
BSE
CNT
CRCE
CNT
DP
CNT
PP
CNT
W
Reset00000000
Reg
Addr
MBAR + 0xB08E
Figure 29-25. USB Counter Overflow Register (CNTOVR)
Table 29-25. CNTOVR Field Descriptions
Bits Name Description
7 — Reserved, should be cleared.
6 TXPCNT Transmitted packet counter overflow flag.
0 The transmitted packet counter has not overflowed.
1 The transmitted packet counter has overflowed.
5 FRMECNT Framing error counter overflow flag.
0 The framing error counter has not overflowed.
1 The framing error counter has overflowed.
4 PIDECNT PID error counter overflow flag.
0 The PID error counter has not overflowed.
1 The PID error counter has overflowed.