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| author | Jens Arnold <amiconn@rockbox.org> | 2004-10-04 17:53:53 +0000 |
|---|---|---|
| committer | Jens Arnold <amiconn@rockbox.org> | 2004-10-04 17:53:53 +0000 |
| commit | 36813086e6fa4bfe75484db20bedbf564b5a2420 (patch) | |
| tree | a094ccdd137b35991feef51943624e62d74ae61f | |
| parent | 0bc2c6cc2cb2e2ff75626f35bfa33e0a8af15355 (diff) | |
| download | rockbox-36813086e6fa4bfe75484db20bedbf564b5a2420.zip rockbox-36813086e6fa4bfe75484db20bedbf564b5a2420.tar.gz rockbox-36813086e6fa4bfe75484db20bedbf564b5a2420.tar.bz2 rockbox-36813086e6fa4bfe75484db20bedbf564b5a2420.tar.xz | |
MMC: 10 % faster reading and 15 % faster writing
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@5161 a1c6a512-1295-4272-9138-f99709370657
| -rw-r--r-- | firmware/drivers/ata_mmc.c | 18 |
1 files changed, 13 insertions, 5 deletions
diff --git a/firmware/drivers/ata_mmc.c b/firmware/drivers/ata_mmc.c index 18864cd..b4006c6 100644 --- a/firmware/drivers/ata_mmc.c +++ b/firmware/drivers/ata_mmc.c @@ -198,32 +198,40 @@ static void setup_sci1(int bitrate_register) static void write_transfer(const unsigned char *buf, int len) { const unsigned char *buf_end = buf + len; + register unsigned char data; /* TODO: DMA */ while (buf < buf_end) { + data = fliptable[(signed char)(*buf++)]; /* bitswap */ while (!(SSR1 & SCI_TEND)); /* wait for end of transfer */ - TDR1 = fliptable[(signed char)(*buf++)]; /* write byte */ + TDR1 = data; /* write byte */ SSR1 = 0; /* start transmitting */ } } +/* don't call this with len == 0 */ static void read_transfer(unsigned char *buf, int len) { - unsigned char *buf_end = buf + len; + unsigned char *buf_end = buf + len - 1; + register signed char data; /* TODO: DMA */ while (!(SSR1 & SCI_TEND)); /* wait for end of transfer */ TDR1 = 0xFF; /* send do-nothing data in parallel */ + SSR1 = 0; /* start receiving first byte */ while (buf < buf_end) { - SSR1 = 0; /* start receiving */ - while (!(SSR1 & SCI_RDRF)); /* wait for data */ - *buf++ = fliptable[(signed char)(RDR1)]; /* read byte */ + while (!(SSR1 & SCI_RDRF)); /* wait for data */ + data = RDR1; /* read byte */ + SSR1 = 0; /* start receiving */ + *buf++ = fliptable[data]; /* bitswap */ } + while (!(SSR1 & SCI_RDRF)); /* wait for last byte */ + *buf = fliptable[(signed char)(RDR1)]; /* read & bitswap */ } /* timeout is in bytes */ |