]>
Commit | Line | Data |
---|---|---|
5e3b071c KR |
1 | ------------------------------------------------------------------------------- |
2 | STMicroelectronics M93C66 Microwire EEPROM | |
3 | ------------------------------------------------------------------------------- | |
4 | ||
5 | This is a set of example captures of the Microwire traffic from a | |
6 | STMicroelectronics M93C66 Microwire EEPROM. | |
7 | ||
8 | Details: | |
9 | http://www.st.com/resource/en/datasheet/m93c86-r.pdf | |
10 | ||
11 | ||
12 | Logic analyzer setup | |
13 | -------------------- | |
14 | ||
15 | The logic analyzer used was an MCU123 Saleae Logic clone (at 4MHz): | |
16 | ||
17 | Probe M93C66 pin | |
18 | ---------------------- | |
19 | 1 S / CS | |
20 | 3 C / SK | |
21 | 4 D / SI | |
22 | 5 Q / SO | |
23 | ||
24 | M93C66 pin 6 (ORG) was tied high to use the x16 memory organisation (i.e., | |
25 | 16-bit words). | |
26 | ||
27 | PulseView was used to capture the trace with the following parameters: | |
28 | ||
29 | - sample rate: 4 MHz | |
30 | - samples: 50 k | |
31 | - trigger: rising channel 1 (CS) | |
32 | - pre-trigger: 5% | |
33 | ||
34 | ||
35 | st_m93c66.sr | |
36 | ------------ | |
37 | ||
38 | The M93C66 EEPROM has the same following marking: | |
39 | ||
40 | C66WP | |
41 | (ST) K431 | |
42 | ||
43 | The communication is initiated by a custom software implementation for a | |
44 | STM32F103C8 using the Microwire protocol as master. | |
45 | ||
46 | The master performs the following actions: | |
47 | ||
48 | - Read 16-bits word 0x4242 at 8-bit address 0x0 | |
49 | - Read first words (4x 0x4242) starting at address 0x0 | |
50 | - Enable write and erase | |
51 | - Erase word at address 0x0 and wait until ready | |
52 | - Erase complete EEPROM and wait until ready | |
53 | - Write word 0x4242 at address 0x0 and wait until ready | |
54 | - Write word 0x4242 on complete EEPROM and wait until ready | |
55 | - Disable write and erase |