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Section 8 I/O Ports
(7)
Pin Functions
The relationship between the register settings and the pin function is shown below.
(a)
Normal Extended Mode
• P47 to P44
The pin function is switched as shown below according to the combination of the CS256E and
IOSE bits in SYSCR, the ADFULLE bit in BCR2 of the BSC, and the P4nDDR bit. Address 13 in
the table below is expressed by the following logical expression.
Address 13 = 1: ADFULLE • CS256E • IOSE
P4nDDR
Address 13
Pin
function
[Legend] n = 15 to 12, n = 7 to 4, X: Don't care
• P43 to P40
Port pins 43 to 40 function as bidirectional data bus pins in 16-bit bus extension, and can be used
as general I/O port pins in 8-bit bus extension.
(b)
Address-Data Multiplex Extended Mode
Port pins 47 to 44 are automatically set to function as address bus pins. Port pins 43 to 40 can be
used as general I/O port pins.
Rev. 1.00 Mar. 12, 2008 Page 294 of 1178
REJ09B0403-0100
0
X
P4n input pin
1
0
Am output pin
1
P4n output pin
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