P321
Data Sheet and User Manual
PG3A Pattern Generator
P321 – Low Speed Serial Probe
January 2009 - Rev 1.2
PG3A Pattern Generator
P321 – Serial probe
1.0 General:
The P321 probe features outputs compatible with four common low-speed serial
communication protocols. They are RS232, RS422, SPI, and I2C.
RS232 support consists of 3 outputs. The nominal drive level is +5/-5 volts on these
outputs.
RS422 support consists of 3 differential outputs.
SPI support consists of 8 outputs. The logic high (Voh) is variable from 2.5 volts to 5.0
volts. The logic low is nominally 0 volts.
I2C support consists of drivers for SCL and SDA. User provides pullup.
2.0 Requirements:
The P321 option works with all current PG3AMod and PG3ACab models. The
instrument firmware must be V1.2 or higher. The PGApp software must be V2.0.010 or
higher. Updated versions of the instrument firmware and the PGApp software can be
freely downloaded from the PG3A website: www.movingpixel.com/PG3A.html.
3.0 Pinouts
The connections to the probe are shown on a label on the probe.
This is the view from the top of the probe.
RSRVD
RSRVD
RSRVD
GND
RSRVD
MOSI
SCLK
GND
GND
GND
VCC
SCL
SDA
GND
TX+
DTR+
RTS+
RSRVD
RSRVD
RSRVD
RS422
I2C
SPI
Top Row
Bottom Row
SPI
RS232
TX
DTR
RTS
GND
GP0
GP1
GP2
GP3
GP4
GP5
GND
RSRVD
RSRVD
GND
TXDTRRTSRSRVD
RSRVD
RSRVD
RS422
Pins are grouped and labeled by protocol.
SPI Pins
MOSI
SCLK
GP0 – GP5
Master Out/Slave In
Serial Clock
General Purpose that can be used as chip selects.
I2C Pins
VCC
SCL
SDA
Connect to Vcc (2V ≤ VCC ≤ 5V) used for the target I2C bus
Connect to the SCL line of the target I2C bus
Connect to the SDA line of the target I2C bus
RS422 Pins
TX+
TXDTR+
DTRRTS+
RTS-
Transmit Data output +
Transmit Data output Data Terminal Ready output +
Data Terminal Ready output Ready to Send output +
Ready to Send output –
RS232 Pins
TX
DTR
RTS
Transmit Data output
Data Terminal Ready output
Ready to Send output
RSRVD Pins
Do not make any connections to these pins
GND Pins
One or more ground pins should be connected to the system-under-test (SUT). There is
no need to connect all GND pins.
4.0 PG Data Channel Assignments
It is envisioned that the user need not ever know this level of detail. Using the “FillGroup-From-File” facility in the GUI, these details are hidden. Nevertheless, some users
may wish to drive data directly. These group assignments are made for the given output
connector to which the probe is connected where “X” represents the group A, B, C, or D
4.1 I2C outputs
X0(0) Ù
SCl (serial clock)
X0(1) Ù
SDA (serial data)
4.2 SPI outputs
X0(0) Ù
SClk (serial clock)
X0(1) Ù
MOSI (serial data to DUT)
X0(2) Ù
GP0 (general purpose signal 0)
X0(3) Ù
GP0 (general purpose signal 1)
X0(4) Ù
GP0 (general purpose signal 2)
X0(5) Ù
GP0 (general purpose signal 3)
X0(6) Ù
GP0 (general purpose signal 4)
X0(7) Ù
GP0 (general purpose signal 5)
4.3 RS232 outputs
X0(0) Ù
TxD (transmit data)
X0(1) Ù
DTR (Data Terminal Ready)
X0(1) Ù
RTS (Ready To Send)
4.4 RS422 outputs
X0(0) Ù
Tx+
X0(1) Ù
DTR+
X0(2) Ù
RTS+
X0(3) Ù
TxX0(4) Ù
DTRX0(5) Ù
RTS-
4.0 Electrical specification for the P321 probe
Characteristic
Output Characteristic
SPI Output voltage high
SPI bit rate
I2C bit rate
RS232 bit rate
RS422 bit rate
Weight
Overall Dimensions
Specification
Min
+2.0 V
Notes
Max
+5.0 V
100 Mbits/s
400 kHz
1 Mbits/s
35 Mbits/s
~140 grams
Length: 130 mm, Width 80
mm, Height: 27 mm
load < 250 pF
100 Ω termination
approximate
approximate