Rainbow Electronics W90P710CDG - Manual (Page 281)

W90P710CD/W90P710CDG
Publication Release Date: September 19, 2006
- 281 - Revision B2
(BSWP=0, HSWP=0)
0000H D[31] P[30] D[29] D[28] D[27] D[26] D[25] D[24]
Pixel 1 Pixel 2 Pixel 3 Pixel 4 Pixel 5 Pixel 6 Pixel 7 Pixel 8
D[23] P[22] D[21] D[20] D[19] D[18] D[17] D[16]
Pixel 9 Pixel 10 Pixel 11 Pixel 12 Pixel 13 Pixel 14 Pixel 15 Pixel 16
D[15] P[14] D[13] D[12] D[11] D[10] D[9] D[8]
Pixel 17 Pixel 18 Pixel 19 Pixel 20 Pixel 21 Pixel 22 Pixel 23 Pixel 24
D[7] P[6] D[5] D[4] D[3] D[2] D[1] D[0]
Pixel 25 Pixel 26 Pixel 27 Pixel 28 Pixel 29 Pixel 30 Pixel 31 Pixel 32
……….
If there is an image with size 480*480, 24bpp, stored in memory device with starting address is
0x30000000. 24bpp means there are 4bytes a pixel (real color 3bytes and dummy data 1byte). So:
FIFO1SADDR
= 0x30000000
FIFO1COLCNT = 0x01E0
FIFO1ROWCNT = 0x01E0
FIFO1REALCOLCNT = 0x01E0
The unit of FIFOCOLCNT is word. So, if the image is 16bpp, FIFO1COLCNT and
FIFO1REALCOLCNT are modified to 0x00F0 because under 16bpp mode, a word contains two pixel
data. When FIFO received the value which FIFOCOLCNT specified, VLINEFINSH interrupt is
generated and
(1) Row counter will increase 1. When row counter received the value which
FIFOROWCNT specified, VFRAMFINSH interrupt is generated. So,
FIFOROWCNT have no concern with BPP.
(2) FIFOSTRIDE will be load in and add to current accessing address
Column counter counts the FIFO writing pulse. If Horizontal Up-Scaling factor is 2X, FIFO will extract
a pixel data to two pixel data internal. So if Horizontal Up-Scaling function is enabled, FIFOCOLCNT
need to divided again or VLINEFINSH interrupt will generated after FIFO have received two column
data and FIFOROWCNT and VFRAMFINSH interrupt will be influenced too.
The same with Horizontal Down-Scaling function, so it’s recommend that Horizontal Down-
Scaling Factor M is a multiple of 4. When VFRAMEFINSH interrupt generated, FIFO will fetch image
data re-start at FIFO1SADDR.