NEC V850E/MA1 User Manual page 496

14.3.13 Port CM
Port CM is a 6-bit I/O port that can be set to the input or output mode in 1-bit units.
7 6
PCM – –
Bit position Bit name
5 to 0
PCMn
(n = 5 to 0)
In addition to their function as port pins, in the control mode, the port CM pins operate as the wait insertion signal
input, internal system clock output/bus clock output, bus hold control signal output, and refresh request signal output
from DRAM.
(1) Operation in control mode
Port
Port CM PCM0 WAIT
PCM1 CLKOUT/BUSCLK
PCM2 HLDAK
PCM3 HLDRQ
PCM4 REFRQ
PCM5 SELFREF
(2) I/O mode/control mode setting
The port CM I/O mode setting is performed by the port CM mode register (PMCM), and the control mode
setting is performed by the port CM mode control register (PMCCM) and the port CM function control register
(PFCCM).
(a) Port CM mode register (PMCM)
This register can be read/written in 8-bit or 1-bit units.
7 6
PMCM 1 1
Bit position Bit name
5 to 0
PMCMn
(n = 5 to 0)
496
CHAPTER 14 PORT FUNCTIONS
5 4 3
PCM5 PCM4 PCM3
Port CM
I/O port
Alternate Function Pin Name
5 4 3
PMCM5 PMCM4 PMCM3
Port Mode
Specifies input/output mode for PCMn pin.
0: Output mode (output buffer on)
1: Input mode (output buffer off)
User's Manual U14359EJ4V0UM
2 1 0
PCM2 PCM1 PCM0
Function
Remark
Wait insertion signal input
Internal system clock output/bus
clock output
Bus hold acknowledge signal
output
Bus hold request signal input
Refresh request signal output
Self-refresh request signal input
2 1 0
PMCM2 PMCM1 PMCM0 FFFFF02CH
Function
Address After reset
FFFFF00CH Undefined
Block Type
D
K
J
D
J
E
Address After reset
FFH