General-Purpose Input/Output (Gpio); Port B Signals And Registers - Freescale Semiconductor DSP56311 User Manual

Programming the Peripherals

5.5 General-Purpose Input/Output (GPIO)

The DSP56311 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 DSP56311 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:
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)

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.
DSP56311
Host Interface
(HI08) Port
5-6
Non-Multiplexed
Bus
H[0–7]
HA0
HA1
HA2
HCS/HCS
Single DS
HRW
HDS/HDS
Single HR
HREQ/HREQ
HACK/HACK
Figure 5-2. Port B Signals
DSP56311 User's Manual, Rev. 2
Multiplexed Port B GPIO
Bus
HAD[0–7] PB[0–7]
HAS/HAS PB8
HA8 PB9
HA9 PB10
HA10 PB13
Double DS
HRD/HRD PB11
HWR/HWR PB12
Double HR
HTRQ/HTRQ PB14
HRRQ/HRRQ PB15
Freescale Semiconductor