IBM EM78P259N/260N EM78P259N/260N, 6.1.6 R5 ~ R6 (Port 5 ~ Port 6) , 6.1.7 R7 (Port 7)

EM78P259N/260N
8-Bit Microprocessor with OTP ROM
Product Specification (V1.2) 05.18.2007 • 9
(This specification is subject to change without further notice)
6.1.6 R5 ~ R6 (Port 5 ~ Port 6)
R5 & R6 are I/O registers
The upper 2 bits of R5 are fixed to “0” (if EM78P259N is selected).
Only the lower 6 bits of R5 are available (this applies to EM78P259N only as
EM78P260N can use all the bits)
6.1.7 R7 (Port 7)
Bit 7 6 5 4 3 2 1 0
EM78P259N/260N ‘0’ ‘0’ ‘0’ ‘0’ ‘0’ ‘0’ ‘0’ I/O
ICE259N C3 C2 C1 C0 RCM1 RCM0 ‘0’ I/O
Note: R7 is an I/O register
For EM78P259N/260N, only the lower 1 bit of R7 is available.
Bit 7 ~ Bit 2:
[With EM78P259N/260N]: Unimplemented, read as ‘0’.
[With Simulator (C3~C0, RCM1, & RCM0)]: are IRC calibration bits in IRC oscillator
mode. Under IRC oscillator mode of ICE259N simulator,
these are the IRC mode selection bits and IRC calibration bits.
Bit 7 ~ Bit 4 (C3 ~ C0): Calibrator of intern al RC mode
C3 C2 C1 C0 Frequency (MHz)
0 0 0 0 (1-36%) x F
0 0 0 1 (1-31.5%) x F
0 0 1 0 (1-27%) x F
0 0 1 1 (1-22.5%) x F
0 1 0 0 (1-18%) x F
0 1 0 1 (1-13.5%) x F
0 1 1 0 (1-9%) x F
0 1 1 1 (1-4.5%) x F
1 1 1 1 F (default)
1 1 1 0 (1+4.5%) x F
1 1 0 1 (1+9%) x F
1 1 0 0 (1+135%) x F
1 0 1 1 (1+18%) x F
1 0 1 0 (1+22.5%) x F
1 0 0 1 (1+27%) x F
1 0 0 0 (1+31.5%) x F
1. Frequency values shown are theoretical and taken at an instance of
a high frequency mode. Hence, frequency values are shown for
reference only. Definite values depend on the actual process.
2. Similar way of calculation is also applicable to low frequency mode.