video4linux/cx2341x/fw-memory.txt

4 Note: the memory long words are little-endian ('intel format').
11 	ivtvctl -O min=0x02000000,max=0x020000ff
14 register space :-).
19 The cx2341x exposes its entire 64M memory space to the PCI host via the PCI BAR0
20 (Base Address Register 0). The addresses here are offsets relative to the
23 0x00000000-0x00ffffff Encoder memory space
24 0x00000000-0x0003ffff Encode.rom
25       ???-???         MPEG buffer(s)
26       ???-???         Raw video capture buffer(s)
27       ???-???         Raw audio capture buffer(s)
28       ???-???         Display buffers (6 or 9)
30 0x01000000-0x01ffffff Decoder memory space
31 0x01000000-0x0103ffff Decode.rom
32       ???-???         MPEG buffers(s)
33 0x0114b000-0x0115afff Audio.rom (deprecated?)
35 0x02000000-0x0200ffff Register Space
43 DMA Registers 0x000-0xff:
45  0x00 - Control:
46 	0=reset/cancel, 1=read, 2=write, 4=stop
47  0x04 - DMA status:
48 	1=read busy, 2=write busy, 4=read error, 8=write error, 16=link list error
49  0x08 - pci DMA pointer for read link list
50  0x0c - pci DMA pointer for write link list
51  0x10 - read/write DMA enable:
52 	1=read enable, 2=write enable
53  0x14 - always 0xffffffff, if set any lower instability occurs, 0x00 crashes
54  0x18 - ??
55  0x1c - always 0x20 or 32, smaller values slow down DMA transactions
56  0x20 - always value of 0x780a010a
57  0x24-0x3c - usually just random values???
58  0x40 - Interrupt status
59  0x44 - Write a bit here and shows up in Interrupt status 0x40
60  0x48 - Interrupt Mask
61  0x4C - always value of 0xfffdffff,
62 	if changed to 0xffffffff DMA write interrupts break.
63  0x50 - always 0xffffffff
64  0x54 - always 0xffffffff (0x4c, 0x50, 0x54 seem like interrupt masks, are
67  0x60-0x7C - random values
68  0x80 - first write linked list reg, for Encoder Memory addr
69  0x84 - first write linked list reg, for pci memory addr
70  0x88 - first write linked list reg, for length of buffer in memory addr
72  0x8c-0xdc - rest of write linked list reg, 8 sets of 3 total, DMA goes here
75  0xe0 - first (and only) read linked list reg, for pci memory addr
76  0xe4 - first (and only) read linked list reg, for Decoder memory addr
77  0xe8 - first (and only) read linked list reg, for length of buffer
78  0xec-0xff - Nothing seems to be in these registers, 0xec-f4 are 0x00000000.
80 Memory locations for Encoder Buffers 0x700-0x7ff:
82 These registers show offsets of memory locations pertaining to each
83 buffer area used for encoding, have to shift them by <<1 first.
86 0x07FC: Encoder SDRAM pre-charge
88 Memory locations for Decoder Buffers 0x800-0x8ff:
90 These registers show offsets of memory locations pertaining to each
91 buffer area used for decoding, have to shift them by <<1 first.
94 0x08FC: Decoder SDRAM pre-charge
101 0x7000: LSB I2C write clock bit (inverted)
102 0x7004: LSB I2C write data bit (inverted)
107 0x9020: GPIO direction (Bit7 (GPIO 0..7) - 0:input, 1:output)
119 interrupt mask 0x0048. If a bit is cleared in the mask, then we want our ISR to
131 19 Decoder VBI re-insertion
132 18 Decoder DMA err (linked-list bad)