Macintosh-SW/mac-rom-simm-programmer
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Got rid of a few magic numbers, cleaned up more code

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This commit is contained in:
Doug Brown 2012-05-13 17:48:35 -07:00
parent d0b50e15c9
commit 6f24f97df5
4 changed files with 24 additions and 70 deletions
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27
external_mem.h
View File

@ -10,6 +10,9 @@
#include <stdint.h>
#include <stdbool.h>
#include "ports.h"
#define NUM_CHIPS 4
// Holds info about the chip (retrieved with JEDEC standards)
struct ChipID
@ -25,14 +28,6 @@ struct ChipID
#define IC4 (1 << 0)
#define ALL_CHIPS (IC1 | IC2 | IC3 | IC4)
// I feel kind of sick making these available to the outside world, but
// I'm doing it for efficiency.
// These are the bits on port B corresponding to the control signals.
// Pass them to ExternalMem_Assert() or ExternalMem_Deassert().
#define SIMM_WE (1 << 6)
#define SIMM_OE (1 << 5)
#define SIMM_CS (1 << 4)
// Initializes the (bit-banged) external memory interface
void ExternalMem_Init(void);
@ -51,23 +46,11 @@ void ExternalMem_SetDataAsInput(void);
// Reads back the value the chips are putting onto the data lines
uint32_t ExternalMem_ReadData(void);
/*// Sets the state of the chip select line
void ExternalMem_AssertCS(void);
void ExternalMem_DeassertCS(void);
// Sets the state of the write enable line
void ExternalMem_AssertWE(void);
void ExternalMem_DeassertWE(void);
// Sets the state of the output enable line
void ExternalMem_AssertOE(void);
void ExternalMem_DeassertOE(void);*/
// This is not the nicest-looking software engineering practice
// in the world, but it saves needlessly wasted CPU cycles
// that would be wasted in layers upon layers of abstraction
#define ExternalMem_Assert(assertMask) PORTB &= ~(assertMask);
#define ExternalMem_Deassert(assertMask) PORTB |= (assertMask);
#define ExternalMem_Assert(assertMask) do { Ports_ControlOff(assertMask); } while (0)
#define ExternalMem_Deassert(assertMask) do { Ports_ControlOn(assertMask); } while (0)
// Reads a set of data from all 4 chips simultaneously
void ExternalMem_Read(uint32_t startAddress, uint32_t *buf, uint32_t len);

42
ports.c
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@ -7,12 +7,6 @@
#include "ports.h"
#include "mcp23s17.h"
#include <avr/io.h>
// SIMM control signals on port B
#define SIMM_WE (1 << 6)
#define SIMM_OE (1 << 5)
#define SIMM_CS (1 << 4)
// Save some time by not changing the register
// unless the value has changed [SPI = relatively slow]
@ -96,42 +90,6 @@ void Ports_DataOut_RMW(uint32_t data, uint32_t modifyMask)
PORTF &= ((modifiedDataOff >> 0) & 0xFF);
}
void Ports_SetCSOut(bool data)
{
if (data)
{
PORTB |= SIMM_CS;
}
else
{
PORTB &= ~SIMM_CS;
}
}
void Ports_SetOEOut(bool data)
{
if (data)
{
PORTB |= SIMM_OE;
}
else
{
PORTB &= ~SIMM_OE;
}
}
void Ports_SetWEOut(bool data)
{
if (data)
{
PORTB |= SIMM_WE;
}
else
{
PORTB &= ~SIMM_WE;
}
}
void Ports_SetAddressDDR(uint32_t ddr)
{
DDRA = (ddr & 0xFF); // A0-A7

21
ports.h
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@ -10,6 +10,7 @@
#include <stdbool.h>
#include <stdint.h>
#include <avr/io.h>
// Under normal operation, we will only be using the address pins as outputs.
// The data pins will switch back and forth between all inputs and all outputs.
@ -19,7 +20,7 @@
// Ports_SetDataOut(),
// Ports_SetAddressDDR() [once at the beginning]
// Ports_SetDataDDR(),
// and Ports_ReadDataInData
// and Ports_ReadData
//
// The reason I have implemented all this functionality is to give me complete
// control over all the pins for other use cases, such as a SIMM electrical test.
@ -27,15 +28,22 @@
// many shorted output/input scenarios. So even though these functions are overkill,
// they will be useful for diagnostics.
// I feel kind of sick making these available to the outside world, but
// I'm doing it for efficiency because they change fairly often.
// These are the bits on port B corresponding to the control signals.
#define SIMM_WE (1 << 6)
#define SIMM_OE (1 << 5)
#define SIMM_CS (1 << 4)
void Ports_Init(void);
void Ports_SetAddressOut(uint32_t data);
void Ports_AddressOut_RMW(uint32_t data, uint32_t modifyMask);
void Ports_SetDataOut(uint32_t data);
void Ports_DataOut_RMW(uint32_t data, uint32_t modifyMask);
void Ports_SetCSOut(bool data);
void Ports_SetOEOut(bool data);
void Ports_SetWEOut(bool data);
#define Ports_SetCSOut(data) do { if (data) Ports_ControlOn(SIMM_CS); else Ports_ControlOff(SIMM_CS); } while (0)
#define Ports_SetOEOut(data) do { if (data) Ports_ControlOn(SIMM_OE); else Ports_ControlOff(SIMM_OE); } while (0)
#define Ports_SetWEOut(data) do { if (data) Ports_ControlOn(SIMM_WE); else Ports_ControlOff(SIMM_WE); } while (0)
void Ports_SetAddressDDR(uint32_t ddr);
void Ports_AddressDDR_RMW(uint32_t ddr, uint32_t modifyMask);
@ -57,4 +65,9 @@ bool Ports_ReadCS(void);
bool Ports_ReadOE(void);
bool Ports_ReadWE(void);
// These two functions are for turning control signals on and off.
// Pass it a mask of SIMM_WE, SIMM_OE, and SIMM_CS.
#define Ports_ControlOn(mask) do { PORTB |= (mask); } while (0)
#define Ports_ControlOff(mask) do { PORTB &= ~(mask); } while (0)
#endif /* PORTS_H_ */

4
usb_serial/usb_serial.c
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@ -113,11 +113,11 @@ void USBSerial_HandleWaitingForCommandByte(uint8_t byte)
// Asked to identify the chips in the SIMM. Identify them and send reply.
case IdentifyChips:
{
struct ChipID chips[4];
struct ChipID chips[NUM_CHIPS];
SendByte(CommandReplyOK);
ExternalMem_IdentifyChips(chips);
int x;
for (x = 0; x < 4; x++)
for (x = 0; x < NUM_CHIPS; x++)
{
SendByte(chips[x].manufacturerID);
SendByte(chips[x].deviceID);