GMS81C1404 Datasheet, PDF (40/93 Pages) Hynix Semiconductor – 8-BIT SINGLE-CHIP MICROCONTROLLERS

GMS81C1404/GMS81C1408
10.3 RC and RCIO registers
RC is an 4-bit bidirectional I/O port (address C4_H). Each
pin can be set individually as input and output through the
RCIO register (address C5_H).
In addition, Port RC is multiplexed with Serial Peripheral
Interface (SPI).
The control register SIOM (address E0_H) controls to select
Serial Peripheral Interface function.
After reset, the RCIO register value is “0”, port may be
used as general I/O ports. To select Serial Peripheral Inter-
face function, write “1” to the corresponding bit of SIOM.
RC Data Register
ADDRESS : C4H
RESET VALUE : Undefined
RC
- RC6 RC5 RC4 RC3 - -
-
INPUT / OUTPUT DATA
RC Direction Register
RCIO
ADDRESS : C5H
RESET VALUE : -0000---
DIRECTION SELECT
0 : INPUT PORT
1 : OUTPUT PORT
Figure 10-4 Registers of Port RC
PORT
RC6/
SOUT
RC5/
SIN
RC4/
SCK
RC3/
SRDY
Function
RC6
SOUT
RC5
SIN
RC4
SCKO
SCKI
RC3
SRDYIN
SRDYOUT
SRDY
X
X
X
X
X
X
X
0
1
1
SIOM
SM [1:0]
X:0
X:1
0:X
1:X
0:0
0:0
0:0
X:X
X:X
X:X
SCK [1:0]
X:X
X:X
X:X
X:X
X:X
00, 01, 10
1:1
X:X
00, 01, 10
1:1
Description
RC6 (Normal I/O Port)
SPI Serial Data Output
RC5 (Normal I/O Port)
SPI Serial Data Input
RC4 (Normal I/O Port)
SPI Synchronous Clock Output
SPI Synchronous Clock Input
RC3 (Normal I/O Port)
SPI Ready Input (Master Mode)
SPI Ready Output (Slave Mode)
Table 10-1 Serial Communication Functions in RC Port
38
June. 2001 Ver 1.2