Rohde Schwarz Rohde & Schwarz HMO1002 2-channel oscilloscope, Digital Storage oscilloscope, 21-1002-RS00 데이터 시트

 ❙No acknowledge to confirm data reception
 ❙Duplex capability

Most SPI buses have 4 common lines, 2 data lines and 2 
control lines:

 ❙Clock to all slaves (SCLK)
 ❙Slave select or chip select lines (SS or CS)
 ❙Master-Out-Slave-In, Slave-Data-Input (MOSI or SDI)
 ❙Master-In-Slave-Out, Slave-Data-Output (MISO or SDO)

If the master generates a clock pulse and selects a slave, 
data can be transmitted in either one direction or 
simultaneously in both directions (only available with 
HOO10/HV110).

Certain settings are necessary to guarantee that a SPI bus 
is decoded correctly. First, you have to determine if a SPI 
system with or without chip select is available (2-wire or 
3-wire SPI). This can be done in the BUS setup menu when 
selecting the BUS type. For a 2-wire SPI system, select the 
option SSPI; for a 3-wire SPI system, select the option SPI. 
Then press the CONFIGURATION button to open the setup 
menu for SPI. Use the top soft menu key SOURCE to se-
lect the respective channel for chip select (CS), clock (Clk) 
and data. Select the respective soft menu key CS, Clk or 
Data and then use the soft menu key DATA and the univer-
sal knob to the select the respective source channel. For 
the 2-wire SPI, select the possible TIME OUT instead of a 
chip select source. During the time out, data and clock line 
are at Low. When the time out has been reached, a new 
frame begins. If the time intervals between the data pa-
ckets are shorter than the time out, these packets belong 
to the same frame. You can select the dead time via uni-
versal knob or via numeric input (KEYPAD button). A small 
window provides information about the current settings.

In addition to assigning the source, the soft menu key AC-
TIVE allows you to select the following settings:

 ❙CS: Chip select high or low active (low active is the 

default setting)

Fig. 13.6: Simple configuration of SPI BUS

Fig. 12.12: Simple configuration of a SPI BUS

for the trigger condition and the address. In most cases, 
the byte offset is zero if the trigger is to occur on the 
maximum first 24 bits after the address. The soft menu
key NUMBER OF BYTES allows you to define how many
bytes are to be analyzed for the trigger condition. The 
input may be binary or hexadecimal (PATTERN INPUT). If 
binary input is selected, the individual bits can be 
assigned to any condition via soft menu key SELECT BIT 
and the universal knob. The soft menu key STATE allows 
you to set the state H (=1), L (=0) or X (don’t care) for 
each bit. The state X defines any state. If the input is
hexadecimal, only the entire byte can be set to X. If you 
choose the hexadecimal input, use the soft menu key 
VALUE and the universal knob to set the respective byte 
value. The soft menu key SELECT BYTE allows you to 
edit the different bytes (byte 1 to byte 2 to byte 3 etc.) 
sequentially (depending on the defined NUMBER OF
BYTES). The active byte will be marked with a green 
border in the display window of the trigger condition (see 
fig. 12.9).

Press the MENU OFF button three times to close all me-
nus, and the oscilloscope will trigger on the set address 
and data.

For measurements without measuring object please refer
to chapter 10.2.5.

The Serial Peripheral Interface SPI is used to communicate 

with slow peripheral devices, in particular for the transfer 
of data streams. The SPI bus was developed by Motorola 
(today known as Freescale); however, it has not been for-
mally standardized. Generally, this is a bus with clock and 
data lines and a select line (3-wire). If only one master and 
one slave are present, the select line may be deleted. This 
type of line is also called SSPI (Simple SPI) (2-wire). A SPI 
BUS has the following properties:

 ❙Master-slave communication
 ❙No instrument addressing

Fig. 13.5: I

2

C BUS