G
galapogos
Hi,
I'm trying to control a Cypress USB-IDE bridge chip to turn on and off
a 2.5" HDD by controlling the chip's power on reset signal. Once the
chip's reset signal(RESET) is pulled low, it will pull the ide reset
signal(ARESET) low also, and release it about 35ms after RESET is
released(verified with a logic analyzer).
I have RESET set at low when I power on the bridge chip/HDD by plugging
in the USB cable, and the HDD isn't detected. Once I pull RESET high,
the HDD is detected. However, when I try to do another reset(pulling
RESET low for 10ms then high again), the HDD is disconnected and not
detected again according to windows explorer or disk management.
However, my logic analyzer shows that the waveforms for both RESET and
ARESET are normal(RESET is low for 10ms, ARESET is low for 45ms).
According to the ATA-6 document that I have, RESET only needs to be low
for 25us, so I'm not going below the standard. Does anyone know why the
HDD is disconnected after a soft reset?
Disconnecting and reconnecting the USB cable after the soft reset
causes windows to detect the HDD again...but I want to be able to
disconnect/connect the HDD without touching the cable. Is the RESET pin
the right pin to be manipulating?
Thanks!
I'm trying to control a Cypress USB-IDE bridge chip to turn on and off
a 2.5" HDD by controlling the chip's power on reset signal. Once the
chip's reset signal(RESET) is pulled low, it will pull the ide reset
signal(ARESET) low also, and release it about 35ms after RESET is
released(verified with a logic analyzer).
I have RESET set at low when I power on the bridge chip/HDD by plugging
in the USB cable, and the HDD isn't detected. Once I pull RESET high,
the HDD is detected. However, when I try to do another reset(pulling
RESET low for 10ms then high again), the HDD is disconnected and not
detected again according to windows explorer or disk management.
However, my logic analyzer shows that the waveforms for both RESET and
ARESET are normal(RESET is low for 10ms, ARESET is low for 45ms).
According to the ATA-6 document that I have, RESET only needs to be low
for 25us, so I'm not going below the standard. Does anyone know why the
HDD is disconnected after a soft reset?
Disconnecting and reconnecting the USB cable after the soft reset
causes windows to detect the HDD again...but I want to be able to
disconnect/connect the HDD without touching the cable. Is the RESET pin
the right pin to be manipulating?
Thanks!