Samsung S3C2440A - Manual (Page 446)

MMC/SD/SDIO CONTROLLER S3C2440A RISC MICROPROCESSOR
19-10
SDI FIFO Status Register(SDIFSTA)
Register Address R/W Description Reset Value
SDIFSTA 0x5A000038 R/(C) SDI FIFO Status Register 0x0
SDIFSTA Bit Description Initial State
Reserved [31:16]
FIFO Reset(FRST) [16]
C
Reset FIFO value. This bit is automatically cleared.
0 = normal mode, 1 = FIFO reset
0
FIFO Fail error
(FFfail)
[15:14]
R/C
FIFO fail error when FIFO occurs overrun / underrun data saving.
This flag is cleared by setting to one these bits.
00 = not detect, 01 = FIFO fail
10 = FIFO fail in the last transfer(only FIFO reset need)
11 = reserved
0
FIFO available
Detect for Tx
(TFDET)
[13] This bit indicates that FIFO data is available for transmit when
DatMode is data transmit mode. If DMA mode is enable, sd host
requests DMA operation.
0 = not detect(FIFO full), 1 = detect(0
≤
FIFO
≤
63)
0
FIFO available
Detect for Rx
(RFDET)
[12] This bit indicates that FIFO data is available for receive when
DatMode is data receive mode. If DMA mode is enable, sd host
requests DMA operation.
0 = not detect(FIFO empty), 1 = detect(1
≤
FIFO
≤
64)
0
Tx FIFO Half Full
(TFHalf)
[11] This bit sets to 1 whenever Tx FIFO is less than 33byte.
0 = 33
≤
Tx FIFO
≤
64, 1 = 0
≤
Tx FIFO
≤
32
0
Tx FIFO Empty
(TFEmpty)
[10] This bit sets to 1 whenever Tx FIFO is empty.
0 = 1
≤
Tx FIFO
≤
64, 1 = Empty(0byte)
0
Rx FIFO Last Data
Ready (RFLast)
[9]
R/C
This bit sets to 1 when Rx FIFO occurs to behave last data of all
block. This flag is cleared by setting to one this bit.
0 = not received yet, 1 = Rx FIFO gets Last data
0
Rx FIFO Full
(RFFull)
[8] This bit sets to 1 whenever Rx FIFO is full.
0 = 0
≤
Rx FIFO
≤
63, 1 = Full(64byte)
0
Rx FIFO Half Full
(RFHalf)
[7] This bit sets to 1 whenever Rx FIFO is more than 31byte.
0 = 0
≤
Rx FIFO
≤
31, 1 = 32
≤
Rx FIFO
≤
64
0
FIFO Count
(FFCNT)
[6:0] Number of data(byte) in FIFO 0000000
* Although the last Rx data size is lager than remained count of FIFO data, you could read this data. If this
event happens, you should clear FFfail field, and FIFO reset field