C8051F120/1/2/3/4/5/6/7
220
Rev. 1.2
19.1.6. External Memory Interface Pin Assignments
If the External Memory Interface (EMIF) is enabled on the Low ports (Ports 0 through 3), EMIFLE (XBR2.5) should
be set to a logic 1 so that the Crossbar will not assign peripherals to P0.7 (/WR), P0.6 (/RD), and if the External Mem-
ory Interface is in Multiplexed mode, P0.5 (ALE). Figure 19.4 shows an example Crossbar Decode Table with
EMIFLE=1 and the EMIF in Multiplexed mode. Figure 19.5 shows an example Crossbar Decode Table with
EMIFLE=1 and the EMIF in Non-multiplexed mode.
If the External Memory Interface is enabled on the Low ports and an off-chip MOVX operation occurs, the External
Memory Interface will control the output states of the affected Port pins during the execution phase of the MOVX
instruction, regardless of the settings of the Crossbar registers or the Port Data registers. The output configuration of
the Port pins is not affected by the EMIF operation, except that Read operations will explicitly disable the output
drivers on the Data Bus. See
Section “18. EXTERNAL DATA MEMORY INTERFACE AND ON-CHIP
XRAM” on page 199
for more information about the External Memory Interface.
Figure 19.4. Priority Crossbar Decode Table
EMIFLE = 1; EMIF in Multiplexed Mode; P1MDIN = 0xFF)
PIN I/O 0
1
2
3
4
5
6
7
0
1
2
3
4
5
6
7
0
1
2
3
4
5
6
7
0
1
2
3
4
5
6
7
TX0
●
RX0
●
SCK
●
●
MISO
●
●
MOSI
●
●
NSS
●
●
NSS is not assigned to a port pin when the SPI is placed in 3-wire mode
SDA
●
● ● ●
● ●
SCL
●
● ●
● ● ●
TX1
●
● ● ●
● ● ● ●
RX1
●
● ●
● ● ● ● ●
CEX0
●
● ● ●
● ● ● ● ● ●
CEX1
●
● ●
● ● ● ● ● ● ●
CEX2
●
●
● ● ● ● ● ● ● ●
CEX3
●
● ● ● ● ● ● ● ●
●
CEX4
●
● ● ● ● ● ● ●
● ●
CEX5
●
● ● ● ● ● ●
● ● ●
ECI
● ● ● ● ●
● ● ● ● ● ● ● ●
● ● ● ●
ECI0E: XBR0.6
CP0
● ● ● ● ●
● ● ● ● ● ● ● ●
● ● ● ● ●
CP0E: XBR0.7
CP1
● ● ● ● ●
● ● ● ● ● ● ● ●
● ● ● ● ● ●
CP1E: XBR1.0
T0
● ● ● ● ●
● ● ● ● ● ● ● ●
● ● ● ● ● ● ●
T0E: XBR1.1
/INT0
● ● ● ● ●
● ● ● ● ● ● ● ●
● ● ● ● ● ● ● ●
INT0E: XBR1.2
T1
● ● ● ● ●
● ● ● ● ● ● ● ●
● ● ● ● ● ● ● ● ●
T1E: XBR1.3
/INT1
● ● ● ● ●
● ● ● ● ● ● ● ●
● ● ● ● ● ● ● ● ● ●
INT1E: XBR1.4
T2
● ● ● ● ●
● ● ● ● ● ● ● ●
● ● ● ● ● ● ● ● ● ● ●
T2E: XBR1.5
T2EX
● ● ● ● ●
● ● ● ● ● ● ● ●
● ● ● ● ● ● ● ● ● ● ● ●
T2EXE: XBR1.6
T4
● ● ● ● ●
● ● ● ● ● ● ● ●
● ● ● ● ● ● ● ● ● ● ● ● ●
T4E: XBR2.3
T4EX
● ● ● ● ●
● ● ● ● ● ● ● ●
● ● ● ● ● ● ● ● ● ● ● ● ● ●
T4EXE: XBR2.4
/SYSCLK
● ● ● ● ●
● ● ● ● ● ● ● ●
● ● ● ● ● ● ● ● ● ● ● ● ● ● ●
SYSCKE: XBR1.7
CNVSTR0
● ● ● ● ●
● ● ● ● ● ● ● ●
● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●
CNVSTE0: XBR2.0
CNVSTR2
● ● ● ● ●
● ● ● ● ● ● ● ●
● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●
CNVSTE2: XBR2.5
ALE
/RD
/W
R
A
IN1
.0
/A
8
A
IN1
.1
/A
9
A
IN1
.2
/A
1
0
A
IN1
.3
/A
1
1
A
IN1
.4
/A
1
2
A
IN1
.5
/A
1
3
A
IN1
.6
/A
1
4
A
IN1
.7
/A
1
5
A8m/
A0
A9m/
A1
A10m/
A
2
A11m/
A
3
A12m/
A
4
A13m/
A
5
A14m/
A
6
A15m/
A
7
AD0/
D0
AD1/
D1
AD2/
D2
AD3/
D3
AD4/
D4
AD5/
D5
AD6/
D6
AD7/
D7
XBR2.2
XBR0.[5:3]
UART0EN:
SPI0EN:
Crossbar Register Bits
XBR0.2
XBR0.1
XBR0.0
SMB0EN:
AIN1 Inputs/Non-muxed Addr H Muxed Addr H/Non-muxed Addr L
Muxed Data/Non-muxed Data
UART1EN:
PCA0ME:
P0
P1
P2
P3
Summary of Contents for C8051F120
Page 2: ...C8051F120 1 2 3 4 5 6 7 2 Rev 1 2 Notes ...
Page 8: ...C8051F120 1 2 3 4 5 6 7 8 Rev 1 2 26 2 Flash Programming Commands 318 26 3 Debug Support 321 ...
Page 16: ...C8051F120 1 2 3 4 5 6 7 16 Rev 1 2 Notes ...
Page 48: ...C8051F120 1 2 3 4 5 6 7 48 Rev 1 2 ...
Page 98: ...C8051F120 1 2 3 4 5 6 7 98 Rev 1 2 ...
Page 106: ...C8051F120 1 2 3 4 5 6 7 106 Rev 1 2 Notes ...
Page 183: ...C8051F120 1 2 3 4 5 6 7 Rev 1 2 183 Notes ...
Page 184: ...C8051F120 1 2 3 4 5 6 7 184 Rev 1 2 ...
Page 214: ...C8051F120 1 2 3 4 5 6 7 214 Rev 1 2 Notes ...