AnsweredAssumed Answered

ad9989b PLL not locking

Question asked by hkozachkov on Jul 18, 2017
Latest reply on Jul 25, 2017 by hkozachkov
I'm trying to bring up a AD9989B, and I've been unable to get the PLL to lock.
The clock signal that the chip is supposed to be locking onto is pictured in the attachment. It is a 40 Mhz clock ... I don't see anything drastically wrong with it, and it's stable. (My scope only has a 200Mhz bandwidth, so that may be why its rounded.)
Video pixel clock trace
I'm operating under the assumption that the sync signals and the data format of the input video shouldn't matter for the purposes of the PLL locking, but in case it does, the input format i'm expecting is 16 Bit YCbCr 4:2:2 with separate syncs.
I've configured input id 1, input style 1, and 16 bit datawidth (REG 0x16[5:4] = 0b11  .. which implied an 8 bit width in the datasheet, but it looks like those values need to doubled to make any sense.)
HPD and Power ON seem to be working.
I'm configured the "Fixed registers that must be set" to the values specified in the datasheet.
I've also made sure the the registers that the data sheet says are fixed and should not be changed from their defaults were set to their defaults, except for setting R0xA5 to 0xC0 and R0xAB to 0x00 as suggested on this forum. As documented elsewhere on this forum, I had also tried increasing the value R0x98 to try to get a PLL
As you can see from the value of R0x9e, the PLL is not locked.
Any suggestions would be greatly appreciated.
Below is a register dump.
 
REG 0x0 = 00000000
REG 0x1 = 00000000
REG 0x2 = 00000000
REG 0x3 = 00000000
REG 0x4 = 00000000
REG 0x5 = 00000000
REG 0x6 = 00000000
REG 0x7 = 00000000
REG 0x8 = 00000000
REG 0x9 = 00000000
REG 0xa = 01000001
REG 0xb = 00001110
REG 0xc = 00111100
REG 0xd = 00011000
REG 0xe = 00000001
REG 0xf = 00010011
REG 0x10 = 00100101
REG 0x11 = 00110111
REG 0x12 = 00000000
REG 0x13 = 00000000
REG 0x14 = 00000000
REG 0x15 = 00000010
REG 0x16 = 00100000
REG 0x17 = 00000000
REG 0x18 = 00000110
REG 0x19 = 01100010
REG 0x1a = 00000100
REG 0x1b = 10101000
REG 0x1c = 00000000
REG 0x1d = 00000000
REG 0x1e = 00011100
REG 0x1f = 10000100
REG 0x20 = 00011100
REG 0x21 = 10111111
REG 0x22 = 00000100
REG 0x23 = 10101000
REG 0x24 = 00011110
REG 0x25 = 01110000
REG 0x26 = 00000010
REG 0x27 = 00011110
REG 0x28 = 00000000
REG 0x29 = 00000000
REG 0x2a = 00000100
REG 0x2b = 10101000
REG 0x2c = 00001000
REG 0x2d = 00010010
REG 0x2e = 00011011
REG 0x2f = 10101100
REG 0x30 = 00000000
REG 0x31 = 00000000
REG 0x32 = 00000000
REG 0x33 = 00000000
REG 0x34 = 00000000
REG 0x35 = 00000000
REG 0x36 = 00000000
REG 0x37 = 00000000
REG 0x38 = 00000000
REG 0x39 = 00000000
REG 0x3a = 00000000
REG 0x3b = 10000000
REG 0x3c = 00000000
REG 0x3d = 00000000
REG 0x3e = 00000000
REG 0x3f = 00000000
REG 0x40 = 00000000
REG 0x41 = 01010000
REG 0x42 = 11100000
REG 0x43 = 01111110
REG 0x44 = 01111000
REG 0x45 = 00000000
REG 0x46 = 00000000
REG 0x47 = 00000000
REG 0x48 = 00000000
REG 0x49 = 00000000
REG 0x4a = 00000000
REG 0x4b = 00000000
REG 0x4c = 00000000
REG 0x4d = 00000000
REG 0x4e = 00000000
REG 0x4f = 00000000
REG 0x50 = 00000000
REG 0x51 = 00000000
REG 0x52 = 00000000
REG 0x53 = 00000000
REG 0x54 = 00000000
REG 0x55 = 00000000
REG 0x56 = 00000000
REG 0x57 = 00000000
REG 0x58 = 00000000
REG 0x59 = 00000000
REG 0x5a = 00000000
REG 0x5b = 00000000
REG 0x5c = 00000000
REG 0x5d = 00000000
REG 0x5e = 00000000
REG 0x5f = 00000000
REG 0x60 = 00000000
REG 0x61 = 00000000
REG 0x62 = 00000000
REG 0x63 = 00000000
REG 0x64 = 00000000
REG 0x65 = 00000000
REG 0x66 = 00000000
REG 0x67 = 00000000
REG 0x68 = 00000000
REG 0x69 = 00000000
REG 0x6a = 00000000
REG 0x6b = 00000000
REG 0x6c = 00000000
REG 0x6d = 00000000
REG 0x6e = 00000000
REG 0x6f = 00000000
REG 0x70 = 00000000
REG 0x71 = 00000000
REG 0x72 = 00000000
REG 0x73 = 00000000
REG 0x74 = 00000000
REG 0x75 = 00000000
REG 0x76 = 00000000
REG 0x77 = 00000000
REG 0x78 = 00000000
REG 0x79 = 00000000
REG 0x7a = 00000000
REG 0x7b = 00000000
REG 0x7c = 00000000
REG 0x7d = 00000000
REG 0x7e = 00000000
REG 0x7f = 00000000
REG 0x80 = 00000000
REG 0x81 = 00000000
REG 0x82 = 00000000
REG 0x83 = 00000000
REG 0x84 = 00000000
REG 0x85 = 00000000
REG 0x86 = 00000000
REG 0x87 = 00000000
REG 0x88 = 00000000
REG 0x89 = 00000000
REG 0x8a = 00000000
REG 0x8b = 00000000
REG 0x8c = 00000000
REG 0x8d = 00000000
REG 0x8e = 00000000
REG 0x8f = 00000000
REG 0x90 = 00000000
REG 0x91 = 00000000
REG 0x92 = 00000000
REG 0x93 = 00000000
REG 0x94 = 11000000
REG 0x95 = 00000000
REG 0x96 = 00000000
REG 0x97 = 00000000
REG 0x98 = 00000111
REG 0x99 = 00000010
REG 0x9a = 00000000
REG 0x9b = 00011000
REG 0x9c = 00111000
REG 0x9d = 01100000
REG 0x9e = 00000000
REG 0x9f = 00000000
REG 0xa0 = 00000000
REG 0xa1 = 00000000
REG 0xa2 = 10000111
REG 0xa3 = 10000111
REG 0xa4 = 00001000
REG 0xa5 = 11000000
REG 0xa6 = 00000000
REG 0xa7 = 00000000
REG 0xa8 = 00000000
REG 0xa9 = 00000000
REG 0xaa = 00000000
REG 0xab = 00000000
REG 0xac = 00000000
REG 0xad = 00000000
REG 0xae = 01000000
REG 0xaf = 00010100
REG 0xb0 = 00000000
REG 0xb1 = 00000000
REG 0xb2 = 00000000
REG 0xb3 = 00000000
REG 0xb4 = 00000000
REG 0xb5 = 00000000
REG 0xb6 = 00000000
REG 0xb7 = 00000000
REG 0xb8 = 10000000
REG 0xb9 = 00000000
REG 0xba = 00000000
REG 0xbb = 00000000
REG 0xbc = 00000000
REG 0xbd = 00000000
REG 0xbe = 00000000
REG 0xbf = 00000000
REG 0xc0 = 00000000
REG 0xc1 = 00000000
REG 0xc2 = 00000000
REG 0xc3 = 00000000
REG 0xc4 = 00000000
REG 0xc5 = 00000000
REG 0xc6 = 00000100
REG 0xc7 = 00000000
REG 0xc8 = 00000000
REG 0xc9 = 00000011
REG 0xca = 00000000
REG 0xcb = 00000000
REG 0xcc = 00000010
REG 0xcd = 00000000

Outcomes