Chapter 12. Universal Serial Bus (USB)
12-25
Register Description and Programming Model
Table 12-15 lists field descriptions for the USB endpoints 1–7 interrupt status registers.
12.3.2.17 USB Endpoint 1–7 Interrupt Mask Registers (EPnIMR)
Figure 12-20 shows the USB endpoint 1–7 interrupt mask register.
Table 12-15. EP
n
ISR Field Descriptions
Bits
Name
Description
15
HALT_ST
Current status of endpoint n. This bit indicates whether endpoint n is currently halted or
active. HALT_ST is set due to a SET_FEATURE request with the endpoint halt feature
selector set or a STALL response to an IN or OUT packet. HALT_ST is cleared by a
CLEAR_FEATURE request with the endpoint halt feature selector set.
0 Endpoint n active
1 Endpoint n halted
14
DIR
Current direction of endpoint n. This bit indicates whether endpoint n is currently
configured as an IN or OUT endpoint.
0 Endpoint n configured as an OUT endpoint
1 Endpoint n configured as an IN endpoint
13
PRES
Endpoint n present. This bit indicates whether or not endpoint n is present in the current
configuration.
0 Endpoint n absent
1 Endpoint n present
12–5
—
Reserved, should be cleared.
4
EOT
End of transfer interrupt. Set when the end of a transfer has been reached. An EOT
interrupt is generated when a packet with a size less than the maximum packet size or
the first zero-length packet following maximum size packets is sent or received. For OUT
endpoints, the EPDPn must be read before clearing this interrupt in order to determine
the number of bytes of remaining data in the FIFO for the last transfer. For OUT
endpoints, any packets received from the host cause a NAK response until the EOT
interrupt is cleared. For IN endpoints, the user must wait until the EOT interrupt is set
before writing the next transfer to the FIFO.
0 No interrupt pending
1 Transfer completed
3
EOP
End of packet interrupt. Set when a packet is successfully sent or received on endpoint n.
0 No interrupt pending
1 Packet sent or received successfully
2
UNHALT
Endpoint unhalt interrupt. Set when the endpoint n HALT_ST bit is cleared.
0 No interrupt pending
1 Endpoint n unhalted
1
HALT
Endpoint halt interrupt. Set when the endpoint n HALT_ST bit is set.
0 No interrupt pending
1 Endpoint n halted
0
FIFO_LVL FIFO threshold level reached interrupt. Indicates that the FIFO level has risen above or
fallen below the level set in the EPCTLn register for OUT or IN endpoints, respectively.
0 No interrupt pending
1 FIFO threshold level reached
Summary of Contents for DigitalDNA ColdFire MCF5272
Page 1: ...MCF5272UM D Rev 0 02 2001 MCF5272 ColdFire Integrated Microprocessor User s Manual ...
Page 38: ...xxxviii MCF5272 User s Manual TABLES Table Number Title Page Number ...
Page 58: ...1 10 MCF5272 User s Manual MCF5272 Specific Features ...
Page 90: ...2 42 MCF5272 User s Manual Exception Processing Overview ...
Page 96: ...3 6 MCF5272 User s Manual MAC Instruction Execution Timings ...
Page 158: ...5 46 MCF5272 User s Manual Motorola Recommended BDM Pinout ...
Page 184: ...7 12 MCF5272 User s Manual Interrupt Controller Registers ...
Page 338: ...13 44 MCF5272 User s Manual Application Examples ...
Page 414: ...18 6 MCF5272 User s Manual PWM Programming Model ...
Page 452: ...19 38 MCF5272 User s Manual Power Supply Pins ...
Page 482: ...20 30 MCF5272 User s Manual Reset Operation ...
Page 492: ...21 10 MCF5272 User s Manual Non IEEE 1149 1 Operation ...