47
Chapter 2
Pin Functions
Preliminary User’s Manual U15839EE1V0UM00
(9)
PAH0 to PAH7 (Port AH) … Input/output
Port AH is an 8-bit input/output port in which input or output can be set in 1-bit units.
Besides functioning as a port, in control mode, this port operates as the address bus (A16 to A23)
for when memory is accessed externally.
An operation mode of port or control mode can be selected for each bit and specified by the port
AH mode control register (PMCAH).
(a) Port mode
PAH0 to PAH7 can be set to input or output in 1-bit units using the port AH mode register (PMAH).
(b) Control mode
PAH0 to PAH7 can be used as A16 to A23 by using PMCAH.
(c) A16 to A23 (Address) … Output
This pin outputs the upper 8-bit address of the 24-bit address in the address bus on an external
access.
(10) PCS0, PCS3, PCS4 (Port CS) … Input/output
Port CS is a 3-bit input/output port in which input or output can be set in 1-bit units.
Besides functioning as a port, in control mode, it operates as a chip-select control signal output
when memory is accessed externally.
An operation mode of port or control mode can be selected for each bit and specified by the port
CS mode control register (PMCCS).
(a) Port mode
PCS0, PCS3, PCS4 can be set to input or output in 1-bit units using the port CS mode register
(PMCS).
(b) Control mode
PCS0, PCS3, PCS4 can be used as CS0, CS3, CS4 by using PMCCS.
(c) CS0, CS3, CS4 (Chip select) … Output
This is the chip select signal for external SRAM, external ROM, or external peripheral I/O.
The signal CSn is assigned to memory block n (n = 0, 3, 4).
This is active for the period during which a bus cycle that accesses the corresponding memory
block is activated.
It is inactive in an idle state (TI).
Summary of Contents for mPD703128
Page 6: ...6 Preliminary User s Manual U15839EE1V0UM00 ...
Page 20: ...20 Preliminary User s Manual U15839EE1V0UM00 ...
Page 32: ...32 Preliminary User s Manual U15839EE1V0UM00 MEMO ...
Page 154: ...154 Preliminary User s Manual U15839EE1V0UM00 MEMO ...
Page 238: ...238 Preliminary User s Manual U15839EE1V0UM00 MEMO ...
Page 356: ...356 Preliminary User s Manual U15839EE1V0UM00 MEMO ...
Page 522: ...522 Preliminary User s Manual U15839EE1V0UM00 MEMO ...
Page 600: ...600 Preliminary User s Manual U15839EE1V0UM00 MEMO ...
Page 610: ...610 Preliminary User s Manual U15839EE1V0UM00 ...
Page 612: ......