em6521 EM Microelectronic, em6521 Datasheet - Page 22

• Manufacturer Part Number: em6521
• Description: Mfp Version Of Em6621 Ultra Low Power Microcontroller With 4x20 Lcd Driver
• Manufacturer: EM Microelectronic

Figure 14. Port SP Terminal Configuration
6.6.2 Pull-up or Pull-down
For each terminal of PSP[3:0] an input pull-up (metal mask MPSPU[n]) or pull-down (metal mask MPSPD[n])
resistor can be implemented per metal mask option (ROM version only). Per default the two metal masks are in
place, so one can chose per software to have either a pull-up, a pull-down or no resistor. For Metal mask
selection and available resistor values refer to chapter Error! Reference source not found.
Pull-down ON : MPSPD[n] must be in place ,
Pull-down OFF: MPSPD[n] is not in place,
Pull-up ON *
Pull-up OFF* : MPSPU[n] is not in place,
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Internal Data Bus
R
: MPSPU[n] must be in place,
AND the bit NoPdPS[n] must be ‘0’ .
OR if MPSPD[n] is in place NoPdPS[n] = ‘1’ cuts off the pull-down.
OR selecting NchOpDPS[n] = ‘1’ cuts off the pull-down.
AND the bit NchOpDPS[n] must be ‘1’ ,
AND ( the bits OM[1,0] in RegSysCntl2 = ‘00’ (input mode) OR any of the port SP terminals
OR if MPSPU[n] is in place NchOpDPS[n] = ‘0’ cuts off the pull-up,
OR if MPSPU[n] is in place and NchOpDPS[n] = ‘1’ then SerPData[n] = 0 cuts off the pull-up.
(SOUT, Ready/CS and SCLK)
Serial Interface
Inputs (SIN
and SCLKIn)
DB[n]
is in output mode with a logic ‘1’ to be driven) .
Serial Interface Outputs
Parallel Output
Data Register
DR[n]
Read
Parallel Output
Read OR Serial Mode
Mode (direction
Terminal only)
for SCLKOut
Tristate
Read
22
MUX
Pull-down Option
Register
Parallel
Control
Serial /
Pd[n]
Nch. Open Drain
Option Register
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EM6521
OD[n]
Mask Option
MPSPU[n]
Active Pull-up
in Nch. Open
Active
Pulldown
I / O Terminal
Drain Mode
Mask Option
MPSPD[n]
SP[n]