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RL78/G1A CHAPTER 12 SERIAL ARRAY UNIT
R01UH0305EJ0200 Rev.2.00 431
Jul 04, 2013
12.3.17 Registers controlling port functions of serial input/output pins
Using the serial array unit requires setting of the registers that control the port functions multiplexed on the target
channel (port mode register (PMxx), port register (Pxx), port input mode register (PIMxx), port output mode register
(POMxx), port mode control register (PMCxx)).
For details, see 4.3.1 Port mode registers (PMxx), 4.3.2 Port registers (Pxx), 4.3.4 Port input mode registers
(PIMxx), 4.3.5 Port output mode registers (POMxx), and 4.3.6 Port mode control registers (PMCxx).
Specifically, using a port pin with a multiplexed serial data or serial clock output function (e.g. P02/ANI17/SO10/TxD1)
for serial data or serial clock output, requires setting the corresponding bits in the port mode control register (PMCxx) and
port mode register (PMxx) to 0, and the corresponding bit in the port register (Pxx) to 1.
When using the port pin in N-ch open-drain output (V
DD tolerance
Note 1
/EVDD tolerance
Note 2
) mode, set the corresponding
bit in the port output mode register (POMxx) to 1. When connecting an external device operating on a different potential
(1.8 V or 2.5 V), see 4.4.5 Handling different potential (1.8 V, 2.5 V) by using I/O buffers.
Example: When P02/ANI17/SO10/TxD1 is to be used for serial data output
Set the PMC02 bit of port mode control register 0 to 0.
Set the PM02 bit of port mode register 0 to 0.
Set the P02 bit of port register 0 to 1.
Specifically, using a port pin with a multiplexed serial data or serial clock input function (e.g.
P03/ANI16/SI10/RxD1/SDA10) for serial data or serial clock input, requires setting the corresponding bit in the port mode
register (PMxx) to 1, and the corresponding bit in the port mode control register (PMCxx) to 0. In this case, the
corresponding bit in the port register (Pxx) can be set to 0 or 1.
When the TTL input buffer is selected, set the corresponding bit in the port input mode register (PIMxx) to 1. When
connecting an external device operating on a different potential (1.8 V or 2.5 V), see 4.4.5 Handling different potential
(1.8 V, 2.5 V) by using I/O buffers.
Example: When P03/ANI16/SI10/RxD1/SDA10 is to be used for serial data input
Set the PMC03 bit of port mode control register 0 to 0.
Set the PM03 bit of port mode register 0 to 1.
Set the P03 bit of port register 0 to 0 or 1.
Notes 1. 25 to 48-pin products
2. 64-pin product