Differences

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--- projects:hi-pi [2017/03/21 04:49]
darron [Appendix]
+++ projects:hi-pi [2017/03/23 05:34] (current)
darron [Appendix]
@@ Line 11: / Line 11: @@
 to reset a device which has low voltage programming mode disabled in its
 configuration bits.
+=== News ===
+A bug may occur with this circuit in certain situations, please refer to the
+appendix.
@@ Line 119: / Line 124: @@
 === Appendix ===
-Thanks must go to Tomas Lorenc who has notified me that on some PICMicros with
+Thanks must go to Tomas Lorenc who has notified me a fix is required
-certain configuration bit settings hi-pi will fail
+for devices which have MCLR configured as an I/O. In this situation
-to bring a device out of reset and into programming mode due to VDD
+a device is not brought out of reset and into programming mode due to VDD
-being presented first. Here he presents a fix for this situation.
+being raised first. Here he presents a fix for this situation.
 {{:projects:hi-pi-mod.png?200}}
+For example, the PIC12F675 has this feature in it's configuration word.
+<code>
+bit5
+MCLRE: GP3/MCLR Pin Function Select bit(5)
+= GP3/MCLR pin function is MCLR
+= GP3/MCLR pin function is digital I/O, MCLR internally tied to VDD
+</code>