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Tidy

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This commit is contained in:
Philip Smart
2020-06-11 00:04:26 +01:00
parent 5fafddb097
commit e4cf08aa25
2 changed files with 21 additions and 11 deletions
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30
common/tranzputer.c
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@@ -7,9 +7,19 @@
// This file contains methods which allow applications to access and control the
// traZPUter board and the underlying Sharp MZ80A host.
// I had considered writing this module in C++ but decided upon C as speed is more
// important and C++ always adds a little additional overhead. Some of the methods need
// to be written as embedded assembler but this is for a later time when using the
// tranZPUter on faster motherboards.
// important and C++ always adds a little additional overhead.
// Even in C a fair bit of overhead is added by the compiler even after optimisation,
// thus the Interrupt Service Routines have been coded as inline assembler to gain
// extra cycles, one of the big problems is capturing the Z80 signals and data
// in order to action commands such as memory switch. Part of the problem is the
// non-uniform allocation of pins - part my problem in the hardware, part Teensy
// in the model of K64F and the pins available which means several GPIO registers
// must be read and pieced together to form a 16bit address bus and 8 bit data
// bus. Fine under normal situations but not ISR, an example is setting the memory
// mode control switch - in C it takes 20uS, after stripping it down of nicities
// such as maps, this comes down to 13uS and further optimisations can be made in
// assembler but 13uS is a long long time even for a 2MHz CPU and when cranked up
// to 8MHz it becomes a challenge!
//
// NB. This library is NOT thread safe. In zOS, one thread is running continually in
// this code but is suspended if zOS launches an application which will call this
@@ -548,13 +558,14 @@ static void __attribute((naked, noinline)) irqPortD(void)
" irqd3: \n"
);
#if 0
// Now save the GPIO values into the structure. Seperate statements to get around the optimizer trying to use 5 scratch registers.
// asm volatile(" str r4, %[val1] \n" : [val1] "=m" (z80Control.portA) : : "r4","r5","r6","r7","r8","r9","r10","r11","r12");
// asm volatile(" str r5, %[val2] \n" : [val2] "=m" (z80Control.portB) : : "r4","r5","r6","r7","r8","r9","r10","r11","r12");
// asm volatile(" str r6, %[val3] \n" : [val3] "=m" (z80Control.portC) : : "r4","r5","r6","r7","r8","r9","r10","r11","r12");
// asm volatile(" str r7, %[val4] \n" : [val4] "=m" (z80Control.portD) : : "r4","r5","r6","r7","r8","r9","r10","r11","r12");
// asm volatile(" str r8, %[val5] \n" : [val5] "=m" (z80Control.portE) : : "r4","r5","r6","r7","r8","r9","r10","r11","r12");
asm volatile(" str r4, %[val1] \n" : [val1] "=m" (z80Control.portA) : : "r4","r5","r6","r7","r8","r9","r10","r11","r12");
asm volatile(" str r5, %[val2] \n" : [val2] "=m" (z80Control.portB) : : "r4","r5","r6","r7","r8","r9","r10","r11","r12");
asm volatile(" str r6, %[val3] \n" : [val3] "=m" (z80Control.portC) : : "r4","r5","r6","r7","r8","r9","r10","r11","r12");
asm volatile(" str r7, %[val4] \n" : [val4] "=m" (z80Control.portD) : : "r4","r5","r6","r7","r8","r9","r10","r11","r12");
asm volatile(" str r8, %[val5] \n" : [val5] "=m" (z80Control.portE) : : "r4","r5","r6","r7","r8","r9","r10","r11","r12");
#endif
// Convert lower 8 address bits into a byte and store.
asm volatile(" lsrs r0, r5, #4 \n" // (z80Control.portB >> 4)&0x80)
@@ -3872,7 +3883,6 @@ void processServiceRequest(void)
// Set the alternate frequency. The TZFS command provides the frequency in KHz so multiply up to Hertz before changing.
case TZSVC_CMD_CPU_CHGFREQ:
printf("Changing to Freq:%ld\n", (svcControl.cpuFreq * 1000));
setZ80CPUFrequency(svcControl.cpuFreq * 1000, 1);
break;

2
include/tranzputer.h
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@@ -35,7 +35,7 @@
// Configurable constants.
//
#define DECODE_Z80_IO 3 // Flag to enable code, via interrupt, to capture Z80 actions on I/O ports an Memory mapped I/O.
#define DECODE_Z80_IO 0 // Flag to enable code, via interrupt, to capture Z80 actions on I/O ports an Memory mapped I/O.
// 0 = No code other than direct service request interrupts.
// 1 = Decode Z80 I/O address operations.
// 2 = Decode Z80 I/O operations with data.