enCoRe™ V CY7C643xx, enCoRe™ V LV CY7C604xx TRM, Document No. 001-32519 Rev *H
148
Full-Speed USB
20.3.3
USBIO_CR0 Register
The USB I/O Control Register 0 (USBIO_CR0) is used for
manually transmitting on the USB D+ and D– pins, or read-
ing the differential receiver.
Bit 7: TEN.
This is used to manually transmit on the D+ and
D– pins. Normally, this bit must be cleared to allow the inter-
nal SIE to drive the pins. The most common reason for man-
ually transmitting is to force a resume state on the bus. ‘0’ is
manual transmission off (TSE0 and TD have no effect). ‘1’ is
manual transmission enabled (TSE0 and TD determine the
state of the D+ and D– pins).
Bit 6: TSE0.
Transmit Single-Ended Zero. SE0: both D+
and D– low. No effect if TEN=0. ‘0’ is do not force SE0. ‘1’ is
force SE0 on D+ and D–.
Bit 5: TD.
Transmit a USB J or K state on the USB bus. No
effect if TEN=0 or TSE0=1. ‘0’ forces USB K state (D+ is
low, D– is high). ‘1’ forces USB J state (D+ is high, D– is
low).
Bit 0: RD.
This read only bit gives the state of the USB dif-
ferential receiver. ‘0’ is D+ < D– or D+ = D– = 0. ‘1’ is D+ >
D–.
For additional information, refer to the
20.3.4
USBIO_CR1 Register
The USB I/O Control Register 1 (USBIO_CR1) is used to
manually read or write the D+ and D– pins, and to configure
internal pull-up resistors on those pins.
Bit 7: IOMode.
This bit allows the D+ and D– pins to be
configured for either USB mode or bit banged modes. If this
bit is set, the DMI and DPI bits are used to drive the D– and
D+ pins. ‘0’ is USB mode. Drive mode has no effect. ‘1’ is
drive mode, DMI and DPI determine state of the D+ and D–
pins.
Bit 6: Drive Mode.
If the IOMode bit is set, this bit config-
ures the D– and D+ pins for either CMOS drive or open
drain drive. If IOMode is cleared, this bit has no effect. Note
that in open drain mode, 5-k
pull-up resistors can be con-
nected internally with the PS2PUEN bit. ‘0’ is D+ and D– are
in open drain mode. If the DPI or DMI bits are set high, the
corresponding D+ or D– pad is high-impedance. ‘1’ is D+
and D– are in CMOS drive mode. D+ follows DPI and D– fol-
lows DMI.
Bit 5: DPI.
This bit is used to drive the D+ pin if IOMode=1.
Refer to the Drive Mode bit for drive state of pad. ‘0’ is drive
D+ pad low. ‘1’ is drive D+ pad high (unless Drive Mode=0).
Bit 4: DMI.
This bit is used to drive the D– pin if IOMode=1.
Refer to the Drive Mode bit for drive state of pad. ‘0’ is drive
D– pad low. ‘1’ is drive D– pad high (unless Drive Mode=0).
Bit 3: PS2PUEN.
This bit controls the connection of the two
internal 5-k
pull-up resistors to the D+ and D– pins. ‘0’ is
no effect. ‘1’ is apply 5k pull ups between Vdd and both D+
and D– pads, independent of the IOMode and Drive Mode
bits.
Bit 2: USBPUEN.
This bit controls the connection of the
internal 1.5-k
pull-up resistor on the D+ pin. ‘0’ is no effect.
‘1’ is apply internal USB pull-up resistor to D+ pad.
Bit 1: DPO.
This read-only bit gives the state of the D+ pin.
Bit 0: DMO.
This read-only bit gives the state of the D– pin.
For additional information, refer to the
Address
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Access
0,34h
TEN
TSE0
TD
RD
# : 0
Address
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Access
0,35h
IOMode
Drive Mode
DPI
DMI
PS2PUEN
USBPUEN
DPO
DMO
# : 03