Bus: SPI (serial peripheral interface).
Connections: four pins (MOSI/MISO/CLOCK/CS) and ground.
Output type: 3.3volt normal, or open collector (pull-up resistors required).
Pull-up resistors: required for open drain output mode (2K – 10K).
Maximum voltage: 5.5volts (5volt safe).
| Syntax | Description |
| A/a/@ | Toggle auxiliary pin. Capital “A” sets AUX high, small “a” sets to ground. @ sets aux to input (high impedance mode) and reads the pin value. |
| D/d | Measure voltage on the ADC pin (v1+ hardware only). |
| W/w | Capital ‘W’ enables the on-board power supplies. Small ‘w’ disables them. (v1+ hardware only). |
| [ | Chip select (CS) active (low). |
| { | CS active (low), show the SPI read byte after every write. |
| ] or } | CS disable (high). |
| R or r | Read one byte by sending dummy byte (0xff). (r:1…255 for bulk reads) |
| 0b | Write this binary value. Format is 0b00000000 for a byte, but partial bytes are also fine: 0b1001. |
| 0h/0x | Write this HEX value. Format is 0h01 or 0×01. Partial bytes are fine: 0xA. A-F can be lower-case or capital letters. |
| 0-255 | Write this decimal value. Any number not preceded by 0x, 0h, or 0b is interpreted as a decimal value. |
| , | Value delimiter. Use a coma or space to separate numbers. Any combination is fine, no delimiter is required between non-number values: {0xa6,0, 0 16 5 0b111 0haF}. |
| & | Delay 1uS. (&:1…255 for multiple delays) |
| (#) | Run macro, (0) for macro list |
| Macro | Description |
| 0 | Macro menu |
| 1 | SPI bus sniffer with configurable CS filter. |
Configuration options
Speed - 30kHz, 125kHz, 250kHz, 1MHz.
Clock polarity - idle low, idle high.
Output clock edge - idle to active, active to idle.
Input sample phase – middle, end.
Output type - open drain/open collector (high=Hi-Z, low=ground) , normal (high=3.3volts, low=ground). Use open drain/open collector output types with pull-up resistors for multi-voltage interfacing.
SPI Bus sniffer
The SPI sniffer is implemented in hardware and should work up to 10MHz. It follows the configuration settings you entered for SPI mode.
- [/] – CS enable/disable
- 0xXX – MOSI read
- (0xXX) – MISO read
SPI CS pin transitions are represented by the normal Bus Pirate syntax. The byte sniffed on the MISO pin is displayed inside ().
SPI>(1)
Sniff when:
1. CS low
2. CS high
3. All traffic
(1) >
SPI bus sniffer, any key exists
[0x30(0x00)0xff(0x12)0xff(0x50)][0x40(0x00)]
The SPI sniffer can read all traffic, or filter by the state of the CS pin. The byte sniffed on the MOSI pin is displayed as a HEX formatted value, the byte sniffed on the MISO pin is inside the ().
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I’m using the bus-pirate (v2go with v3.1FW) to sniff a SPI port, I sometimes get an output in the terminal which isn’t correctly HEX formatted, for example: 0×0x01F.
Any ideas of what is causing this? -
Oh nevermind.. I’m sniffing continuous 8Mhz SPI data, so the little BusPirate isn’t happy as it is over running the buffer. I really should be using a logic analyser instead.
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I think there is a bug in CS sniffing. It’s set like an output and goes low after entering sniffing mode, then goes up after exiting sniffing mode.
Anyone got the same behaviour?
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