Microchip Technology DM183037 Data Sheet
PIC18F97J94 FAMILY
DS30575A-page 532
2012 Microchip Technology Inc.
27.2.4
USB ENDPOINT CONTROL
Each of the 16 possible bidirectional endpoints has its
own independent control register, UEPn (where ‘n’
represents the endpoint number). Each register has an
identical complement of control bits.
own independent control register, UEPn (where ‘n’
represents the endpoint number). Each register has an
identical complement of control bits.
provides the prototype.
The EPHSHK bit (UEPn<4>) controls handshaking for
the endpoint; setting this bit enables USB handshaking.
Typically, this bit is always set except when using
isochronous endpoints.
The EPCONDIS bit (UEPn<3>) is used to enable or
disable USB control operations (SETUP) through the
endpoint. Clearing this bit enables SETUP transac-
tions. Note that the corresponding EPINEN and
EPOUTEN bits must be set to enable IN and OUT
the endpoint; setting this bit enables USB handshaking.
Typically, this bit is always set except when using
isochronous endpoints.
The EPCONDIS bit (UEPn<3>) is used to enable or
disable USB control operations (SETUP) through the
endpoint. Clearing this bit enables SETUP transac-
tions. Note that the corresponding EPINEN and
EPOUTEN bits must be set to enable IN and OUT
transactions. For Endpoint 0, this bit should always be
cleared since the USB specifications identify
Endpoint 0 as the default control endpoint.
The EPOUTEN bit (UEPn<2>) is used to enable or
disable USB OUT transactions from the host. Setting
this bit enables OUT transactions. Similarly, the
EPINEN bit (UEPn<1>) enables or disables USB IN
transactions from the host.
The EPSTALL bit (UEPn<0>) is used to indicate a
STALL condition for the endpoint. If a STALL is issued
on a particular endpoint, the EPSTALL bit for that end-
point pair will be set by the SIE. This bit remains set
until it is cleared through firmware or until the SIE is
reset.
cleared since the USB specifications identify
Endpoint 0 as the default control endpoint.
The EPOUTEN bit (UEPn<2>) is used to enable or
disable USB OUT transactions from the host. Setting
this bit enables OUT transactions. Similarly, the
EPINEN bit (UEPn<1>) enables or disables USB IN
transactions from the host.
The EPSTALL bit (UEPn<0>) is used to indicate a
STALL condition for the endpoint. If a STALL is issued
on a particular endpoint, the EPSTALL bit for that end-
point pair will be set by the SIE. This bit remains set
until it is cleared through firmware or until the SIE is
reset.
REGISTER 27-4:
UEPn: USB ENDPOINT n CONTROL REGISTER (UEP0 THROUGH UEP15)
U-0
U-0
U-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
—
—
—
EPHSHK
EPCONDIS
EPOUTEN
EPINEN
EPSTALL
bit 7
bit 0
Legend:
R = Readable bit
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
x = Bit is unknown
bit 7-5
Unimplemented: Read as ‘0’
bit 4
EPHSHK: Endpoint Handshake Enable bit
1 = Endpoint handshake is enabled
0 = Endpoint handshake is disabled (typically used for isochronous endpoints)
1 = Endpoint handshake is enabled
0 = Endpoint handshake is disabled (typically used for isochronous endpoints)
bit 3
EPCONDIS: Bidirectional Endpoint Control bit
If EPOUTEN = 1 and EPINEN = 1:
1 = Disables Endpoint n from control transfers; only IN and OUT transfers are allowed
0 = Enables Endpoint n for control (SETUP) transfers; IN and OUT transfers are also allowed
If EPOUTEN = 1 and EPINEN = 1:
1 = Disables Endpoint n from control transfers; only IN and OUT transfers are allowed
0 = Enables Endpoint n for control (SETUP) transfers; IN and OUT transfers are also allowed
bit 2
EPOUTEN: Endpoint Output Enable bit
1 = Endpoint n output is enabled
0 = Endpoint n output is disabled
1 = Endpoint n output is enabled
0 = Endpoint n output is disabled
bit 1
EPINEN: Endpoint Input Enable bit
1 = Endpoint n input is enabled
0 = Endpoint n input is disabled
1 = Endpoint n input is enabled
0 = Endpoint n input is disabled
bit 0
EPSTALL: Endpoint Stall Indicator bit
1 = Endpoint n has issued one or more STALL packets
0 = Endpoint n has not issued any STALL packets
1 = Endpoint n has issued one or more STALL packets
0 = Endpoint n has not issued any STALL packets