This is an automated email from Gerrit. Sean Cross ([email protected]) just uploaded a new patch set to Gerrit, which you can find at http://openocd.zylin.com/3707
-- gerrit commit 531f2394fab51aa5f3e52d4de233dc76e4ae3351 Author: Sean Cross <[email protected]> Date: Thu Aug 18 05:16:29 2016 +0000 jtag: drivers: bcm2835gpio: set 4ma drive, slow slew rate Both the drive strength and slew rate are currently set to very high values. This causes the waveforms to overshoot and be less reliable when operating at high speed. This patch lowers the slew rate and sets the drive strength to 4ma, improving the waveform output. Change-Id: I761d35cd64bc54a9e94043904ef00a003b056af0 Signed-off-by: Sean Cross <[email protected]> diff --git a/src/jtag/drivers/bcm2835gpio.c b/src/jtag/drivers/bcm2835gpio.c index 1622b22..a41caf0 100644 --- a/src/jtag/drivers/bcm2835gpio.c +++ b/src/jtag/drivers/bcm2835gpio.c @@ -468,8 +468,8 @@ static int bcm2835gpio_init(void) return ERROR_JTAG_INIT_FAILED; } - /* set 16mA drive strength */ - pads_base[BCM2835_PADS_GPIO_0_27_OFFSET] = 0x5a000018 + 7; + /* set 4mA drive strength, slew rate limited, hysteresis on */ + pads_base[BCM2835_PADS_GPIO_0_27_OFFSET] = 0x5a000008 + 1; tdo_gpio_mode = MODE_GPIO(tdo_gpio); tdi_gpio_mode = MODE_GPIO(tdi_gpio); -- ------------------------------------------------------------------------------ _______________________________________________ OpenOCD-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/openocd-devel
