DSP56303 FREESCALE [Freescale Semiconductor, Inc], DSP56303 Datasheet - Page 98

• Manufacturer Part Number: DSP56303
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

Programming the Peripherals
5.5 General-Purpose Input/Output (GPIO)
The DSP56303 provides 34 bidirectional signals that can be configured as GPIO signals or as
peripheral dedicated signals. No dedicated GPIO signals are provided. All of these signals are
GPIO by default after reset. The control register settings of the DSP56303 peripherals determine
whether these signals function as GPIO or as peripheral dedicated signals. This section describes
how signals can be used as GPIO.
Chapter 2, Signals/Connections details the special uses of the 34 bidirectional signals. These
signals fall into five groups and are controlled separately or as a group:
5.5.1 Port B Signals and Registers
Each of the 16 Port B signals not used as an HI08 signal can be configured as a GPIO signal.
Three registers control the GPIO functionality of Port B: host control register (HCR), host port
GPIO data register (HDR), and host port GPIO direction register (HDDR). Chapter 6, Host
Interface (HI08), discusses these registers.
5-6
Port B: 16 GPIO signals (shared with the HI08 signals)
Port C: six GPIO signals (shared with the ESSI0 signals)
Port D: six GPIO signals (shared with the ESSI1 signals)
Port E: three GPIO signals (shared with the SCI signals)
Timers: three GPIO signals (shared with the triple timer signals)
Host Interface
(HI08) Port
DSP56303
Figure 5-2. Port B Signals
DSP56303 User’s Manual, Rev. 2
Non-Multiplexed
Bus
H[0–7]
HA0
HA1
HA2
HCS/HCS
Single DS
HRW
HDS/HDS
Single HR
HREQ/HREQ
HACK/HACK
HAS/HAS
HA8
HA9
HA10
Double DS
HRD/HRD
HWR/HWR
Double HR
HTRQ/HTRQ
Multiplexed
Bus
HAD[0–7]
HRRQ/HRRQ
Port B GPIO
PB[0–7]
PB8
PB9
PB10
PB13
PB11
PB12
PB14
PB15
Freescale Semiconductor