Datasheet

Chapter 6 Parallel Input/Output Control
MC9S08SH32 Series Data Sheet, Rev. 2
Freescale Semiconductor 77
6.3 Ganged Output
The MC9S08SH32 Series devices contain a feature that allows for up to eight port pins to be tied together
externally to allow higher output current drive. The ganged output drive control register (GNGC) is a
write-once register that is used to enabled the ganged output feature and select which port pins will be used
as ganged outputs. The GNGEN bit in GNGC enables ganged output. The GNGPS[7:1] bits are used to
select which pin will be part of the ganged output.
When GNGEN is set, any pin that is enabled as a ganged output will be automatically configured as an
output and follow the data, drive strength and slew rate control of PTC0. The ganged output drive pin
mapping is shown in Table 6-1.
NOTE
See the DC characteristics in the electrical section for maximum Port I/O
currents allowed for this MCU.
When a pin is enabled as ganged output, this feature will have priority over
any digital module. An enabled analog function will have priority over the
ganged output pin. See Table 2-1 for information on pin priority.
Table 6-1. Ganged Output Pin Enable
GNGC Register Bits
GNGPS7 GNGPS6 GNGPS5 GNGPS4 GNGPS3 GNGPS2 GNGPS1 GNGEN
1
1
Ganged output on PTC3-PTC0 not available on 16-pin packages, however PTC0 control registers are still used to control
ganged output.
Port Pin
2
2
When GNGEN = 1, PTC0 is forced to an output, regardless of the value in PTCDD0 in PTCDD.
PTB5 PTB4 PTB3 PTB2 PTC3 PTC2 PTC1 PTC0
Data Direction
Control
Pin is automatically configured as output when pin is enabled as ganged output.
Data
Control
PTCD0 in PTCD controls data value of output
Drive Strength
Control
PTCDS0 in PTCDS controls drive strength of output
Slew Rate
Control
PTCSE0 in PTCSE controls slew rate of output
PRELIMINARY