path: root/README-DEVELOPERS.lyx
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authorMichael Buesch <>2010-04-02 16:46:35 +0200
committerMichael Buesch <>2010-04-02 16:46:35 +0200
commit09bf3788373c753d3eb4fb9b99af19ded1d9771d (patch)
tree1e286b84424eca95cfbe7c07d432d693e64b5d89 /README-DEVELOPERS.lyx
parent4c2b27be85f6ce39e19cb0c13cae8c50ba7c23cf (diff)
cmdFPGAReadRaw() does not inc the status reg pointer
Document that. Signed-off-by: Michael Buesch <>
Diffstat (limited to 'README-DEVELOPERS.lyx')
1 files changed, 6 insertions, 8 deletions
index a2c62c3..8922808 100644
@@ -258,13 +258,6 @@ address
is used for address latching on the FPGA.
- The microcontroller's status register has an automagically incrementing
- pointer.
- So issueing several cmdFPGAReadRaw() in a row will result in all the bytes
- being put one after each other into the status register.
- The status register can hold up to 64 bytes.
- Reading the status register (cmdReadStatusReg()) will reset the automagic
- pointer to zero.
\begin_layout Subsection
@@ -272,13 +265,18 @@ cmdFPGAReadByte()
\begin_layout Standard
-This is a shortcut to cmdFPGAReadRaw(0x10).
+This is cmdFPGAReadRaw(0x10) with auto-increment.
In general it is used for payload data reading.
Using cmdFPGAReadByte() instead of cmdFPGAReadRaw(0x10) is more efficient
for payload reading, because on the USB bus the command is only one byte
wide instead of two.
So it uses up less space in the transmission queue and can thus speed up
+ It also automagically increments the status register pointer.
+ So several cmdFPGAReadByte() calls in a row will result in the data put
+ next to each other into the status register.
+ This way up to 64bytes can be queued up and be read by one single status
+ register read.
\begin_layout Subsection cgit interface