lf4415 LOGIC Devices Inc., lf4415 Datasheet - Page 15

• Manufacturer Part Number: lf4415
• Description: Video Memory / Fifo
• Manufacturer: LOGIC Devices Inc.

NOTES:
1. Overriding the Write address is only possible during Single-Channel modes. Holding WSET0 LOW for multiple cycles allows multi-cycle or ‘full-time’ Write address override
- with the address capable of changing every cycle
2. Upon detecting a falling F-bit in the TRS preamble (assuming Register 9[7] is set), the write pointer is cleared - with the beginning of the TRS preamble referenced to
address zero. The ‘FFF’ word is written to address 0000, the first ‘000’ word is written to address 0001, etc. The first active sample is therefore written to address 0004.
LOGIC Devices Incorporated
5
RESET WCLK WEN WCLR WSET RDWR
Figure 7 - Write Address Pointer Control
0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
X
0
0
0
1
1
0
0
0
0
0
0
0
0
0
0
Address Control
X
1
0
1
1
1
1
1
1
1
1
1
1
1
1
1
www.logicdevices.com
X
1
1
1
1
1
1
1
1
1
1
1
1
0
0
1
X
X
X
X
X
X
X
X
X
X
X
X
X
X
0
0
[1]
ADDR D11-0 PrevAdd Addr. Description
Am
An
X
X
X
X
X
X
X
X
X
X
X
X
X
X
XXX
XXX
XYZ
FFF
000
000
D1
D2
D3
D4
D5
D6
D7
D8
D9
X
15
0000
0001
0000
0001
0001
0001
0002
0003
0004
0005
0006
0004
0005
Am
An
X
Am+1
0000
0001
0000
0001
0001
0001
0002
0003
0004
0005
0006
0004
0005
Am
An
PRELIMINARY
Master reset - write/read pointers are cleared
Increment write pointer - write D1 to addr. 1
Clear write pointer - write D2 to addr. 0
Increment write pointer - write D3 to addr. 1
Halt write pointer - no write operation
Halt write pointer - no write operation
Increment write pointer - write D4 to addr 2
Increment write pointer - write FFF to addr 3 (begin EAV/SAV)
Increment write pointer - write 000 to addr 4
Increment write pointer - write 000 to addr 5
Increment write pointer - write XYZ to addr 6
Write pointer cleared (assuming falling F-bit detected - Register 9[7])
Increment write pointer - write D6 to addr. 1
Ext. Addr. Port address override - write D7 to addr. “An” **
Ext. Addr. Port address override - write D8 to addr. “Am” **
Increment write pointer - write D9 to addr “Am+1”
High Performance Memory Product
Video Memory / FIFO
MEMORY
FRAME
January 23, 2008 LDS-44xx-A
LF4460
LF4430
LF4415
[2]