ST10F269-T3
Pin P3.12 (BHE/WRH) is another pin with an
alternate output function, however, its structure is
slightly different.
After reset the BHE or WRH function must be
used depending on the system start-up
configuration. In either of these cases, there is no
possibility to program any port latches before.
Thus, the appropriate alternate function is
selected automatically. If BHE/WRH is not used in
the system, this pin can be used for general
purpose I/O by disabling the alternate function
(BYTDIS = 鈥?鈥?/ WRCFG=鈥?鈥?.
Figure 29 :
Block Diagram of Pins P3.15 (CLKOUT) and P3.12 (BHE/WRH)
Write DP3.x
鈥?鈥?/div>
Direction
Latch
Read DP3.x
Alternate
Function
Enable
1
MUX
0
Internal Bus
Write P3.x
Alternate
Data
Output
1
MUX
0
Output
Buffer
P3.12/BHE
P3.15/CLKOUT
Port Output
Latch
Read P3.x
Clock
1
MUX
0
Input
Latch
x = 15, 12
Note: Enabling the BHE or WRH function automatically enables the P3.12 output driver. Setting bit
DP3.12=鈥?鈥?is not required.
During bus hold pin P3.12 is switched back to its standard function and is then controlled by
DP3.12 and P3.12. Keep DP3.12 = 鈥?鈥?in this case to ensure floating in hold mode.
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