PIC16LF819T-E/SO Microchip Technology, PIC16LF819T-E/SO Datasheet - Page 135

• Manufacturer Part Number: PIC16LF819T-E/SO
• Description: IC PIC MCU FLASH 2KX14 18SOIC
• Manufacturer: Microchip Technology
• Series: PIC® 16Fr

Specifications of PIC16LF819T-E/SO

• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 10MHz
• Connectivity: I²C, SPI
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 16
• Program Memory Size: 3.5KB (2K x 14)
• Program Memory Type: FLASH
• Eeprom Size: 256 x 8
• Ram Size: 256 x 8
• Voltage - Supply (vcc/vdd): 2 V ~ 5.5 V
• Data Converters: A/D 5x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 125°C
• Package / Case: 18-SOIC (7.5mm Width)
• Lead Free Status / RoHS Status: Request inventory verification / Request inventory verification

TABLE 14-1:
TABLE 14-2:
The UOE signal toggles the state of the external
transceiver. This line is pulled low by the device to
enable the transmission of data from the SIE to an
external device.
14.2.2.3
The PIC18F2450/4450 devices have built-in pull-up
resistors designed to meet the requirements for low-
speed and full-speed USB. The UPUEN bit (UCFG<4>)
enables the internal pull-ups. Figure 14-1 shows the
pull-ups and their control.
14.2.2.4
The PIC18F2450/4450 devices require an external
pull-up resistor to meet the requirements for low-speed
and full-speed USB. Either an external 3.3V supply or
the V
up resistor must be 1.5 kΩ (±5%) as required by the
USB specifications. Figure 14-3 shows an example
with the V
FIGURE 14-3:
14.2.2.5
The usage of ping-pong buffers is configured using the
PPB1:PPB0 bits. Refer to Section 14.4.4 “Ping-Pong
Buffering” for a complete explanation of the ping-pong
buffers.
© 2008 Microchip Technology Inc.
Note:
VPO
VP
0
0
1
1
0
0
1
1
Microcontroller
USB
The above setting shows a typical connection for a
full-speed configuration using an on-chip regulator
and an external pull-up resistor.
pin may be used to pull up D+ or D-. The pull-
PIC
VMO
USB
VM
0
1
0
1
0
1
0
1
®
Internal Pull-up Resistors
Pull-up Resistors
Ping-Pong Buffer Configuration
V
pin.
USB
D+
D-
DIFFERENTIAL OUTPUTS TO
TRANSCEIVER
SINGLE-ENDED INPUTS
FROM TRANSCEIVER
EXTERNAL CIRCUITRY
1.5 kΩ
Single-Ended Zero
Single-Ended Zero
Illegal Condition
Differential ‘0’
Differential ‘1’
High Speed
Low Speed
Bus State
Bus State
Error
Controller/HUB
Host
14.2.2.6
The USB OE monitor provides indication as to whether
the SIE is listening to the bus or actively driving the bus.
This is enabled by default when using an external
transceiver or when UCFG<6> = 1.
The USB OE monitoring is useful for initial system
debugging, as well as scope triggering during eye
pattern generation tests.
14.2.2.7
An automatic eye pattern test can be generated by the
module when the UCFG<7> bit is set. The eye pattern
output will be observable based on module settings,
meaning that the user is first responsible for configuring
the SIE clock settings, pull-up resistor and Transceiver
mode. In addition, the module has to be enabled.
Once UTEYE is set, the module emulates a switch from
a receive to transmit state and will start transmitting a
J-K-J-K bit sequence (K-J-K-J for full speed). The
sequence will be repeated indefinitely while the Eye
Pattern Test mode is enabled.
Note that this bit should never be set while the module
is connected to an actual USB system. This test mode
is intended for board verification to aid with USB certi-
fication tests. It is intended to show a system developer
the noise integrity of the USB signals which can be
affected by board traces, impedance mismatches and
proximity to other system components. It does not
properly test the transition from a receive to a transmit
state. Although the eye pattern is not meant to replace
the more complex USB certification test, it should aid
during first order system debugging.
14.2.2.8
The PIC18F2450/4450 devices have a built-in 3.3V
regulator to provide power to the internal transceiver and
provide a source for the external pull-ups. An external
220 nF (±20%) capacitor is required for stability.
The regulator is disabled by default and can be enabled
through the VREGEN Configuration bit. When enabled,
the voltage is visible on pin V
is disabled, a 3.3V source must be provided through
the V
transceiver is disabled, V
Note:
Note 1: Do not enable the internal regulator if an
USB
2: V
PIC18F2450/4450
pin for the internal transceiver. If the internal
The drive from V
drive an external pull-up in addition to the
internal transceiver.
external regulator is connected to V
V
disabled.
USB Output Enable Monitor
Eye Pattern Test Enable
Internal Regulator
USB
DD
must be greater than or equal to
at all times, even with the regulator
USB
is not used.
USB
USB
. When the regulator
is sufficient to only
DS39760D-page 133
USB
.